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  Subjects -> SCIENCES: COMPREHENSIVE WORKS (Total: 426 journals)
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AAS Open Research     Open Access   (Followers: 1)
ABC Journal of Advanced Research     Open Access  
Accountability in Research: Policies and Quality Assurance     Hybrid Journal   (Followers: 22)
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Acta Nova     Open Access   (Followers: 1)
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Advanced Science     Open Access   (Followers: 13)
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American Academic & Scholarly Research Journal     Open Access   (Followers: 6)
American Journal of Applied Sciences     Open Access   (Followers: 27)
American Journal of Humanities and Social Sciences     Open Access   (Followers: 16)
ANALES de la Universidad Central del Ecuador     Open Access   (Followers: 4)
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Applied Mathematics and Nonlinear Sciences     Open Access   (Followers: 1)
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ARO. The Scientific Journal of Koya University     Open Access  
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Data     Open Access   (Followers: 5)
Data Curation Profiles Directory     Open Access   (Followers: 5)
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Digithum     Open Access   (Followers: 2)
Discover Sustainability     Open Access   (Followers: 3)
Einstein (São Paulo)     Open Access  
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Elkawnie : Journal of Islamic Science and Technology     Open Access  
Emergent Scientist     Open Access  
Enhancing Learning in the Social Sciences     Open Access   (Followers: 9)
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Estação Científica (UNIFAP)     Open Access   (Followers: 1)
Ethiopian Journal of Education and Sciences     Open Access   (Followers: 6)
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Ethiopian Journal of Sciences and Sustainable Development     Open Access   (Followers: 5)
European Online Journal of Natural and Social Sciences     Open Access   (Followers: 12)
European Scientific Journal     Open Access   (Followers: 10)
Evidência - Ciência e Biotecnologia - Interdisciplinar     Open Access  
Exchanges : the Warwick Research Journal     Open Access   (Followers: 2)
Experimental Results     Open Access   (Followers: 2)
Extensionismo, Innovación y Transferencia Tecnológica     Open Access   (Followers: 3)
Facets     Open Access  
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Fırat University Turkish Journal of Science & Technology     Open Access  
Fontanus     Open Access  
Forensic Science Policy & Management: An International Journal     Hybrid Journal   (Followers: 376)
Frontiers for Young Minds     Open Access  
Frontiers in Climate     Open Access   (Followers: 3)
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Gaudium Sciendi     Open Access   (Followers: 1)
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Ghana Studies     Full-text available via subscription   (Followers: 15)
Global Journal of Pure and Applied Sciences     Full-text available via subscription  
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HardwareX     Open Access  
Heidelberger Jahrbücher Online     Open Access  
Heliyon     Open Access  
Himalayan Journal of Science and Technology     Open Access   (Followers: 1)
History of Science and Technology     Open Access   (Followers: 1)
Hoosier Science Teacher     Open Access  
Iberoamerican Journal of Science Measurement and Communication     Open Access   (Followers: 1)
Impact     Open Access   (Followers: 2)
Indian Journal of History of Science     Hybrid Journal   (Followers: 2)
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Indonesian Journal of Science and Mathematics Education     Open Access   (Followers: 4)
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Ingenieria y Ciencia     Open Access   (Followers: 1)
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Instruments     Open Access  
Integrated Research Advances     Open Access  
Interciencia     Open Access   (Followers: 1)
Interface Focus     Full-text available via subscription  
International Annals of Science     Open Access  
International Archives of Science and Technology     Open Access  
International Journal of Academic Research in Business, Arts & Science     Open Access   (Followers: 2)
International Journal of Advanced Multidisciplinary Research and Review     Open Access  
International Journal of Applied Science     Open Access  
International Journal of Basic and Applied Sciences     Open Access   (Followers: 4)
International Journal of Computational and Experimental Science and Engineering (IJCESEN)     Open Access  
International Journal of Culture and Modernity     Open Access   (Followers: 3)
International Journal of Engineering, Science and Technology     Open Access  
International Journal of Innovation and Applied Studies     Open Access   (Followers: 12)
International Journal of Innovative Research and Scientific Studies     Open Access   (Followers: 6)
International Journal of Network Science     Hybrid Journal   (Followers: 3)
International Journal of Recent Contributions from Engineering, Science & IT     Open Access   (Followers: 1)
International Journal of Research in Science     Open Access   (Followers: 2)
International Journal of Science & Emerging Technologies     Open Access   (Followers: 1)
International Journal of Social Sciences and Management     Open Access   (Followers: 3)
International Journal of Technology Policy and Law     Hybrid Journal   (Followers: 7)
International Letters of Social and Humanistic Sciences     Open Access   (Followers: 1)
International Review of Applied Sciences     Open Access  
InterSciencePlace     Open Access   (Followers: 1)
Investiga : TEC     Open Access  
Investigación Joven     Open Access  
Investigación Valdizana     Open Access  
Investigacion y Ciencia     Open Access   (Followers: 1)
Iranian Journal of Science and Technology, Transactions A : Science     Hybrid Journal  
iScience     Open Access   (Followers: 2)
Issues in Science & Technology     Free   (Followers: 7)
Ithaca : Viaggio nella Scienza     Open Access  
J : Multidisciplinary Scientific Journal     Open Access  
Jaunujų mokslininkų darbai     Open Access   (Followers: 1)
Journal de la Recherche Scientifique de l'Universite de Lome     Full-text available via subscription   (Followers: 2)
Journal of Chromatography & Separation Techniques     Open Access   (Followers: 12)
Journal of Advanced Research     Open Access   (Followers: 3)
Journal of Al-Qadisiyah for Pure Science     Open Access   (Followers: 1)
Journal of Alasmarya University     Open Access   (Followers: 2)
Journal of Analytical Science & Technology     Open Access   (Followers: 6)
Journal of Applied Science and Technology     Full-text available via subscription   (Followers: 1)
Journal of Applied Sciences and Environmental Management     Open Access   (Followers: 3)
Journal of Big History     Open Access   (Followers: 3)
Journal of Composites Science     Open Access   (Followers: 3)
Journal of Critical Thought and Praxis     Open Access   (Followers: 2)
Journal of Deliberative Mechanisms in Science     Open Access  
Journal of Diversity Management     Open Access   (Followers: 6)
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Journal of Interaction Science     Open Access   (Followers: 1)
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Journal of Composites Science
Number of Followers: 3  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2504-477X
Published by MDPI Homepage  [238 journals]
  • J. Compos. Sci., Vol. 5, Pages 164: Numerical Modelling of Bond Strength
           in Overmoulded Thermoplastic Composites

    • Authors: Bernd-Arno Behrens, Klaus Dröder, Kai Brunotte, Hendrik Wester, André Hürkamp, Tim Ossowski, Ralf Lorenz
      First page: 164
      Abstract: Overmoulding of thermoplastic composites combines the steps of thermoforming and injection moulding in an integrated manufacturing process. The combination of continuous fibre-reinforced thermoplastics with overmoulded polymer enables the manufacturing of highly functionally integrated structures with excellent mechanical properties. When performed as a one-shot process, an economically efficient manufacturing of geometrical complex lightweight parts within short cycle times is possible. However, a major challenge in the part and process design of overmoulded thermoplastic composites (OTC) is the assurance of sufficient bond strength between the composite and the overmoulded polymers. Within the framework of a simulation-based approach, this study aims to develop a methodology for predicting the bond strength in OTC using simulation data and a numerical model formulation of the bonding mechanisms. Therefore, a modelling approach for the determination of the bond strength depending on different process parameters is presented. In order to validate the bond strength model, specimens are manufactured with different process settings and mechanical tests are carried out. Overall, the results of the numerical computation are in good agreement with the experimentally determined bond strength. The proposed modelling approach enables the prediction of the local bond strength in OTC, considering the interface conditions and the processing history.
      Citation: Journal of Composites Science
      PubDate: 2021-06-23
      DOI: 10.3390/jcs5070164
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 165: Investigation of the Phase Transitions
           and Magneto-Electric Response in the
           0.9(PbFe0.5Nb0.5)O3-0.1Co0.6Zn0.4Fe1.7Mn0.3O4 Particulate Composite

    • Authors: Krishnamayee Bhoi, Smaranika Dash, Sita Dugu, Dhiren K. Pradhan, Anil K. Singh, Prakash N. Vishwakarma, Ram S. Katiyar, Dillip K. Pradhan
      First page: 165
      Abstract: Multiferroic composites with enhanced magneto-electric coefficient are suitable candidates for various multifunctional devices. Here, we chose a particulate composite, which is the combination of multiferroic (PbFe0.5Nb0.5O3, PFN) as matrix and magnetostrictive (Co0.6Zn0.4Fe1.7Mn0.3O4, CZFMO) material as the dispersive phase. The X-ray diffraction analysis confirmed the formation of the composite having both perovskite PFN and magnetostrictive CZFMO phases. The scanning electron micrograph (SEM) showed dispersion of the CZFMO phase in the matrix of the PFN phase. The temperature-dependent magnetization curves suggested the transition arising due to PFN and CZFMO phase. The temperature-dependent dielectric study revealed a second-order ferroelectric to the paraelectric phase transition of the PFN phase in the composite with a small change in the transition temperature as compared to pure PFN. The magnetocapacitance (MC%) and magnetoimpedance (MI%) values (obtained from the magneto-dielectric study at room temperature (RT)) at 10 kHz were found to be 0.18% and 0.17% respectively. The intrinsic magneto-electric coupling value for this composite was calculated to be 0.14 mVcm−1Oe−1, which is comparable to other typical multiferroic composites in bulk form. The composite PFN-CZFMO exhibited a converse magneto-electric effect with a change in remanent magnetization value of −58.34% after electrical poling of the material. The obtained outcomes from the present study may be utilized in the understanding and development of new technologies of this composite for spintronics applications.
      Citation: Journal of Composites Science
      PubDate: 2021-06-24
      DOI: 10.3390/jcs5070165
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 166: Study on Indium (III) Oxide/Aluminum
           Thermite Energetic Composites

    • Authors: Pierre Gibot, Estelle Puel
      First page: 166
      Abstract: Thermites or composite energetic materials are mixtures made of fuel and oxidizer particles at micron-scale. Thermite reactions are characterized by high adiabatic flame temperatures (>1000 °C) and high heats of reaction (>kJ/cm3), sometimes combined with gas generation. These properties strongly depend on the chemical nature of the couple of components implemented. The present work focuses on the use of indium (III) oxide nanoparticles as oxidizer in the elaboration of nanothermites. Mixed with an aluminum nanopowder, heat of reaction of the resulting Al/In2O3 energetic nanocomposite was calculated and its reactive performance (sensitivity thresholds regarding different stimuli (impact, friction, and electrostatic discharge) and combustion velocity examined. The Al/In2O3 nanothermite, whose heat of reaction was determined of about 11.75 kJ/cm3, was defined as insensitive and moderately sensitive to impact and friction stimuli and extreme sensitive to spark with values >100 N, 324 N, and 0.31 mJ, respectively. The spark sensitivity was decreased by increasing In2O3 oxidizer (27.71 mJ). The combustion speed in confined geometries experiments was established near 500 m/s. The nature of the oxidizer implemented herein within a thermite formulation is reported for the first time.
      Citation: Journal of Composites Science
      PubDate: 2021-06-26
      DOI: 10.3390/jcs5070166
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 167: Numerical Study of Soil-Thawing Effect
           of Composite Piles Using GMsFEM

    • Authors: Petr V. Sivtsev, Piotr Smarzewski, Sergey P. Stepanov
      First page: 167
      Abstract: During construction works, it is advisable to prevent strong thawing and an increase in the moisture content of the foundations of engineering structures in the summer. Since the density of water and ice differ, due to the difference bulging of the foundation sections can occur when it freezes back in winter. In this work, the effect of fiber-reinforced piles on the thermal field of the surrounding soil is investigated numerically; that is, the study of the influence of aggregates with high and low thermal-physical properties on the temperature of frozen soils is conducted. Basalt and steel fiber reinforcement are compared. The difficulty of this work is that the inclusions inside piles are too small compared to the pile itself. Therefore, to solve the Stefan problem, a generalized multiscale finite element method (GMsFEM) was used. In the GMsFEM, the usual conforming partition of the domain into a coarse grid was used. It allowed reducing problem size and, consequently, accelerating the calculations. Results of the multiscale solution were compared with fine-scale solution, the accuracy of GMsFEM was investigated, and the optimal solution parameters were defined. Therefore, GMsFEM was shown to be well suited for the designated task. Collation of basalt and steel fiber reinforcement showed a beneficial effect of high thermal conductive material inclusion on freezing of piles in winter.
      Citation: Journal of Composites Science
      PubDate: 2021-06-28
      DOI: 10.3390/jcs5070167
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 168: The Effect of Pre-Bond Contamination
           by Thermal Degradation and De-Icing Fluid on the Tensile Strength of Scarf
           Composite Bonded Joints

    • Authors: Konstantinos Tserpes, Elli Moutsompegka
      First page: 168
      Abstract: The synergistic effect of pre-bond contamination by thermal degradation and de-icing fluid on the tensile behavior of scarf composite bonded joints has been investigated experimentally. The contamination types considered are related to the repair process of composite aircraft structures. Three contamination scenarios have been considered: namely, thermal degradation (TD) and a combination of thermal degradation with two different levels of de-icing fluid (TD+DI1 and TD+DI2). DI2 is more severe than DI1. Contamination has been applied to one of the adherents while the other one has been intentionally left intact. Tension tests have been conducted on single-lap shear specimens. The experimental results were compared with the reference samples (REF) showing an increase in tensile strength for the TD specimens and a decrease in tensile strength for the TD+DI1 and TD+DI2 specimens. After the tension tests, the failure surfaces were evaluated to get a better insight of the failure mechanisms of the bondline and to assess the effect of contamination. The TD specimens presented an increased cohesive failure which is consistent with the increase of the failure load, while the combined contamination caused the failure of the composite adherents which again is consistent with the decrease of tensile strength of the scarf specimens.
      Citation: Journal of Composites Science
      PubDate: 2021-06-28
      DOI: 10.3390/jcs5070168
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 169: Design of Tooling System and
           Identifying Crucial Processing Parameters for NFPC Manufacturing in
           Automotive Applications

    • Authors: Vardaan Chauhan, Timo Kärki, Juha Varis
      First page: 169
      Abstract: The aim of this study was to design a tooling system for manufacturing automotive components using a natural fiber polymer composite (NFPC) material. As a case study, an automotive battery cover was selected and a compression molding tool was designed, keeping in mind the need for the simplicity of the tool and ensuring the low cost of this process. However, since the original part was injection-molded with virgin polypropene, some vital changes made in the part and tool design process were documented as a guideline to show new designers how to approach the design of parts and tools using a natural fiber polymer composite material. Additionally, the challenges faced during the manufacturing of composite parts with the new tool were also documented and solutions to these challenges were suggested for large-scale production. Finally, compressive testing was performed to evaluate the performance of the structure of the designed part and to compare the recycled polymer with NFPC material. Both wood and palm fiber composite material perform better in compression testing compared to the recycled polymer material.
      Citation: Journal of Composites Science
      PubDate: 2021-06-29
      DOI: 10.3390/jcs5070169
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 170: Finite Element Analysis for Nonlinear
           Unbonded Circular Fiber-Reinforced Elastomeric Bearings

    • Authors: Pablo Castillo Ruano, Alfred Strauss
      First page: 170
      Abstract: In recent years, interest in low-cost seismic isolation systems has increased. The replacement of the steel reinforcement in conventional elastomeric bearings for a carbon fiber reinforcement is a possible solution and has garnered increasing attention. To investigate the response of fiber-reinforced elastomeric bearings (FREBs) under seismic loads, it is fundamental to understand its mechanical behavior under combined vertical and horizontal loads. An experimental investigation of the components presents complexities due to the high loads and displacements tested. The use of a finite element analysis can save time and resources by avoiding partially expensive experimental campaigns and by extending the number of geometries and topologies to be analyzed. In this work, a numerical model for carbon fiber-reinforced bearings is implemented, calibrated, and validated and a set of virtual experiments is designed to investigate the behavior of the bearings under combined compressive and lateral loading. Special focus is paid to detailed modeling of the constituent materials. The elastomeric matrix is modeled using a phenomenological rheological model based on the hyperelastic formulation developed by Yeoh and nonlinear viscoelasticity. The model aims to account for the hysteretic nonlinear hyper-viscoelastic behavior using a rheological formulation that takes into consideration hyperelasticity and nonlinear viscoelasticity and is calibrated using a series of experiments, including uniaxial tension tests, planar tests, and relaxation tests. Special interest is paid to capturing the energy dissipated in the unbonded fiber-reinforced elastomeric bearing in an accurate manner. The agreement between the numerical results and the experimental data is assessed, and the influence of parameters such as shape factor, aspect ratio, vertical pressure, and fiber reinforcement orientation on stress distribution in the bearings as well as in the mechanical properties is discussed.
      Citation: Journal of Composites Science
      PubDate: 2021-06-29
      DOI: 10.3390/jcs5070170
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 171: Evaluating Impact Damage of Flat
           

    • Authors: Youchao Sun, Yuemei Zhang, Yadong Zhou, Haitao Zhang, Haijun Zeng, Kun Yang
      First page: 171
      Abstract: Bird-strike failure of fan blades is one of the basic challenges for the safety of aircraft engines. Simplified flat blade-like plates are always used for damage mechanism study of composite laminates. One undesirable issue is the failure at the root of clamped flat plates under high-velocity impact. For this purpose, two different strategies were exploited to obtain desirable impact damage distributions, namely the impact location and the boundary condition. Numerical models of the simplified flat blade-like plate and the bird projectile were constructed by using finite element method (FEM) and smoothed particle hydrodynamics (SPH) approaches. The impact damage distributions were comparatively investigated in detail. The numerical results show that changing the boundary condition is the most effective way to obtain preferable impact damages for further failure analysis of real fan blades. Present results will be useful to the future surrogate experimental design of simplified bird-strike testing.
      Citation: Journal of Composites Science
      PubDate: 2021-06-30
      DOI: 10.3390/jcs5070171
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 172: High Strength and High Electrical
           Conductivity Al Nanocomposites for DC Transmission Cable Applications

    • Authors: Abdolreza Javadi, Shuaihang Pan, Chezheng Cao, Xiaochun Li
      First page: 172
      Abstract: Aluminum is one of the most abundant lightweight metals on Earth with broad practical applications, such as in electrical wires. Although traditional aluminum manufacturing by alloying, deformation and thermomechanical means addresses the balance between high strength and high conductivity, adding metallic ceramic nanoparticles into the aluminum matrix can be an exciting alternative approach to mass produce aluminum electrical wires. Here, we show a new class of aluminum nanocomposite electrical conductors (ANECs), with significantly higher hardness (130 HV) and good electrical conductivity (41% IACS). This ANEC is composed of Al and dispersed TiB2 nanoparticles, as confirmed by XRD scanning and SEM imaging. We further observed an unusual ultra-fine grain (UFG) size when slow cooling ANEC samples, as a grain as small as 300 nm was clearly captured in FIB images. We believe that the significant hardness enhancement can be partially attributed to the UFG. Our investigation and theoretical analysis further validated that UFG can be achieved when nanoparticles are uniformly dispersed and distributed in the aluminum matrix, and this understanding is important for the development of Al nanocomposite wires with high strength and high electrical conductivity.
      Citation: Journal of Composites Science
      PubDate: 2021-07-01
      DOI: 10.3390/jcs5070172
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 173: Conducting Polymeric Composites Based
           on Intrinsically Conducting Polymers as Electromagnetic Interference
           Shielding/Microwave Absorbing Materials—A Review

    • Authors: Bluma Guenther Soares, Guilherme M. O. Barra, Tamara Indrusiak
      First page: 173
      Abstract: The development of sophisticated telecommunication equipment and other electro-electronic devices resulted in a kind of electromagnetic pollution that affects the performance of other equipment as well as the health of human beings. Intrinsically conducting polymers (ICP), mainly polyaniline and polypyrrole, have been considered as promising candidates for applications in efficient electromagnetic interference shielding (EMI) due to their ease of preparation, light weight, good conductivity and corrosion resistance. One of the important advantages of these materials is the capability to interact with the EM radiation through both absorption and reflection mechanisms thus enlarging the field of application. In this context, this review article describes a recent overview of the existing methods to produce intrinsically conducting polymers and their blends for electromagnetic shielding application. Additionally, it highlights the relationship between preparation methods reported in the literature with the structure and properties, such as electrical conductivity, electromagnetic shielding effectiveness (EMI SE), complex permittivity and permeability of these materials. Furthermore, a brief theory related to the electromagnetic mechanism and techniques for measuring the microwave absorbing properties are also discussed.
      Citation: Journal of Composites Science
      PubDate: 2021-07-04
      DOI: 10.3390/jcs5070173
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 174: Synthesis of MRGO Nanocomposites as a
           Potential Photocatalytic Demulsifier for Crude Oil-in-Water Emulsion

    • Authors: Zhen Yin Lau, Ko Shyn Tan, Cheng Seong Khe, Chin Wei Lai, Kok Yeow You, Wai Kian Tan
      First page: 174
      Abstract: Oil-in-water (O/W) emulsion has been a major concern for the petroleum industry. A cost-effective magnetite-reduced graphene oxide (MRGO) nanocomposite was synthesized to study the demulsification process of emulsion using said nanocomposite under solar illumination. Characterization data show that the magnetite was successfully deposited on reduced graphene oxide through redox reaction at varying loading amounts of magnetite. Demulsification of the O/W emulsion using MRGO nanocomposite shows that in general the demulsification efficiency was dependent on the loading amount of Fe3O4 on the RGO sheet. It was proposed that the surfactant hydroxyl groups have an affinity towards Fe3O4, which the loading amount was directly proportionate to available active site in Fe3O4. As the loading amount increases, charge recombination centers on the RGO sheet would increase, effectively affecting the charge distribution within MRGO structure.
      Citation: Journal of Composites Science
      PubDate: 2021-07-04
      DOI: 10.3390/jcs5070174
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 175: Effect of Mercerization/Alkali Surface
           Treatment of Natural Fibres and Their Utilization in Polymer Composites:
           Mechanical and Morphological Studies

    • Authors: Deepak Verma, Kheng Lim Goh
      First page: 175
      Abstract: Environmental pollution, such as air, water, and soil pollution, has become the most serious issue. Soil pollution is a major concern as it generally affects the lands and makes them non-fertile. The main cause of soil pollution is agro-waste. It may be possible to mitigate the agro-waste pollution by re-utilizing this agro-waste, namely natural fibres (NFs), by blending into polymer-based material to reinforce the polymer composite. However, there are pros and cons to this approach. Consequently, the polymer composite materials fabricated using NFs are inferior to those polymer composites that are reinforced by, e.g., carbon or glass fibres from the mechanical properties’ perspectives. The limitations of utilizing natural fibres in polymer matrix are their high moisture absorption, resulting in high swelling rate and degradation, inferior resistance to fire and chemical, and inferior mechanical properties. In particular, the NF polymer composites exhibit inferior interfacial adhesion between the fibre and the matrix, which, if improved, ultimately overcome all the listed limitations and improve the mechanical properties of the developed composites. To improve the interfacial adhesion leading to the enhancement of the mechanical properties, optimum chemical treatment such as Alkalization/Mercerization of the fibres have been explored. This article discusses the Mercerization/Alkali surface treatment method for NFs and its effects on the fibres regarding the Mercerization/Alkali surface treatment method for NFs and its effect on the fibres regarding their utilization in the polymer composites, the morphological features, and mechanical properties of composites.
      Citation: Journal of Composites Science
      PubDate: 2021-07-04
      DOI: 10.3390/jcs5070175
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 176: Investigation of the Deformation
           Behaviour and Resulting Ply Thicknesses of Multilayered Fibre–Metal
           Laminates

    • Authors: Missam Irani, Moritz Kuhtz, Mathias Zapf, Madlen Ullmann, Andreas Hornig, Maik Gude, Ulrich Prahl
      First page: 176
      Abstract: Multilayered fibre–metal laminates (FMLs) are composed of metal semifinished products and fibre-reinforced plastics, and benefit from the advantages of both material classes. Light metals in combination with fibre-reinforced thermoplastics are highly suitable for mass production of lightweight structures with good mechanical properties. As the formability of light metal sheets is sometimes limited at room temperature, increasing the process temperature is an appropriate approach to improve formability. However, the melting of thermoplastic materials and resulting loss of stiffness limit the processing temperature. Since single-ply layers have different through-thickness stiffnesses, the forming process changes the ply thickness of the multilayered laminate. In the present study, the deformation behaviour of multilayered FMLs was investigated using a two-dimensional finite-element model assuming plane strain. The thermoelastic-plastic finite-element analysis made investigation of the variation in thickness made possible by incorporating sufficient mesh layers in the thickness direction. The results indicate that a thermoelastic-plastic finite-element model can predict the delamination of plies during deformation, as well as in the final product. Additionally, the predicted changes in thickness of the plies are in good agreement with experimental results when a temperature-dependent friction coefficient is used.
      Citation: Journal of Composites Science
      PubDate: 2021-07-06
      DOI: 10.3390/jcs5070176
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 177: Effect of Wood Fiber Surface Treatment
           on the Properties of Recycled HDPE/Maple Fiber Composites

    • Authors: Roberto C. Vázquez Fletes, Denis Rodrigue
      First page: 177
      Abstract: This work reports on the production and characterization of recycled high density polyethylene (R-HDPE) composites reinforced with maple fibers. The composites were produced by a simple dry-blending technique followed by compression molding. Furthermore, a fiber surface treatment was performed using a coupling agent (maleated polyethylene, MAPE) in solution. FTIR, TGA/DTG, and density analyses were performed to confirm any changes in the functional groups on the fiber surface, which was confirmed by SEM-EDS. As expected, the composites based on treated fiber (TC) showed improved properties compared to composites based on untreated fiber (UC). In particular, MAPE was shown to substantially improve the polymer–fiber interface quality, thus leading to better mechanical properties in terms of tensile modulus (23%), flexural modulus (54%), tensile strength (26%), and flexural strength (46%) as compared to the neat matrix. The impact resistance also increased by up to 87% for TC as compared to UC. In addition, the maximum fiber content to produce good parts increased from 15 to 75 wt% when treated fiber was used. These composites can be seen as sustainable materials and possible alternatives for the development of low-cost building/construction/furniture applications.
      Citation: Journal of Composites Science
      PubDate: 2021-07-07
      DOI: 10.3390/jcs5070177
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 178: Densification of Ceramic Matrix
           Composite Preforms by Si2N2O Formed by Reaction of Si with SiO2 under High
           Nitrogen Pressure. Part 1: Materials Synthesis

    • Authors: Brice Taillet, René Pailler, Francis Teyssandier
      First page: 178
      Abstract: Ceramic matrix composites (CMCs) have been designed and developed for extreme operating environments. The aim of the present study is to look for a rapid densification process providing a high level of material performance. The fibrous preform was made of Hi-Nicalon S fibers woven in a 3D interlock weave. The matrix was composed of Si2N2O prepared inside the CMCs by reacting a mixture of Si and SiO2 under high nitrogen pressure (1 to 3 MPa). Silica was either impregnated by slurry or obtained by oxidation of silicon grains inside the preform. The synthesis reaction was initiated by heating the impregnated preform by means of a carbon resistor submitted to Joule effect. Composition, homogeneity and porosity of the formed matrix were studied and interpreted as a function of the experimental parameters (nitrogen pressure, heating rate of the preform) as well as the recorded thermal history of the process. The present results show that the matrix formation is almost completed in less than one minute. Melting of silicon has a major influence on the process. Competition was observed between the formation of Si3N4 and Si2N2O, which could be mainly controlled by the heating rate of the preform and the nitrogen partial pressure.
      Citation: Journal of Composites Science
      PubDate: 2021-07-07
      DOI: 10.3390/jcs5070178
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 179: Densification of Ceramic Matrix
           Composite Preforms by Si2N2O Formed by Reaction of Si with SiO2 under High
           Nitrogen Pressure. Part 2: Materials Properties

    • Authors: Brice Taillet, René Pailler, Francis Teyssandier
      First page: 179
      Abstract: Ceramic matrix composites (CMCs) have been prepared and optimized as already described in part I of this paper. The fibrous preform made of Hi-Nicalon S fibers was densified by a matrix composed of Si2N2O prepared inside the CMC by reacting a mixture of Si and SiO2 under high nitrogen pressure. This part describes the oxidation resistance and mechanical properties of the optimized CMC. The CMC submitted to oxidation in wet oxygen at 1400 °C for 170 h exhibited an oxidation gradient from the surface to almost the center of the sample. In the outer part of the sample, Si2N2O, Si3N4 and SiC were oxidized into silica in the cristobalite-crystallized form. The matrix microstructure looks similar to the original one at the center of the sample, while at the surface large pores are observed and the fiber/matrix interphase is consumed by oxidation. The elastic modulus and the hardness measured at room temperature by nano-indentation are, respectively, 100 and 8 GPa. The elastic modulus measured at room temperature by tensile tests ranges from 150 to 160 GPa and the ultimate yield strength from 320 to 390 MPa, which corresponds to a yield strain of about 0.6%. The yield strength identified by acoustic emission is about 40 MPa.
      Citation: Journal of Composites Science
      PubDate: 2021-07-08
      DOI: 10.3390/jcs5070179
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 180: Influence of Transition Metals (Cu and
           Co) on the Carbon-Coated Nickel Sulfide Used as Positive Electrode
           Material in Hybrid Supercapacitor Device

    • Authors: Souvik Ghosh, Aparna Paul, Prakas Samanta, Bhau Landge, Sanjib Kumar Mandal, Sangam Sinha, Gour Gopal Dutta, Naresh Chandra Murmu, Tapas Kuila
      First page: 180
      Abstract: Herein, a facile, environment-friendly and cost-effective approach was followed for the preparation of metal sulfide-based supercapacitor electrodes. The effect of transition metal interrogation on the morphology and electrochemical performance of carbon-coated nickel sulfide composite electrode was investigated. Physicochemical characterization showed that the enhancement in electrical conductivity and electrochemical reaction sites with the introduction of copper (Cu) and cobalt (Co) was due to the variation in morphology. Fast ionic transformation and improvement in the number of redox active sites might improve the supercapacitor performance. The electrochemical experiment showed that the NCoSC electrode exhibited the highest capacitance value of ~760 F g−1 at 2 A g−1 current density as compared to the NCuSC and NSC electrodes. Therefore, a hybrid supercapacitor (HSC) device was fabricated by using NCoSC as the positive electrode and thermally reduced graphene oxide (TRGO) as the negative electrode. The fabricated device demonstrated maximum energy density of ~38.8 Wh Kg−1 and power density of 9.8 kW Kg−1. The HSC device also showed ~89.5% retention in specific capacitance after 10,000 charge–discharge cycles at 12 A g−1 current density. So, the tuning of electronic and physical properties by the introduction of Cu and Co on nickel sulfide improved the supercapacitor performance.
      Citation: Journal of Composites Science
      PubDate: 2021-07-08
      DOI: 10.3390/jcs5070180
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 181: Graphene, Graphene-Derivatives and
           Composites: Fundamentals, Synthesis Approaches to Applications

    • Authors: Dibyani Sahu, Harekrushna Sutar, Pragyan Senapati, Rabiranjan Murmu, Debashis Roy
      First page: 181
      Abstract: Graphene has accomplished huge notoriety and interest from the universe of science considering its exceptional mechanical physical and thermal properties. Graphene is an allotrope of carbon having one atom thick size and planar sheets thickly stuffed in a lattice structure resembling a honeycomb structure. Numerous methods to prepare graphene have been created throughout a limited span of time. Due to its fascinating properties, it has found some extensive applications to a wide variety of fields. So, we believe there is a necessity to produce a document of the outstanding methods and some of the novel applications of graphene. This article centres around the strategies to orchestrate graphene and its applications in an attempt to sum up the advancements that has taken place in the research of graphene.
      Citation: Journal of Composites Science
      PubDate: 2021-07-09
      DOI: 10.3390/jcs5070181
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 182: Effects of Electron Beam Irradiation
           on 3D-Printed Biopolymers for Bone Tissue Engineering

    • Authors: Conrad Mastalerz, Isabelle Vroman, Xavier Coqueret, Sébastien Alix
      First page: 182
      Abstract: Implanting scaffolds designed for the regeneration or the replacement of bone tissue damaged by diseases and injuries requires specially designed biomaterials that promote cell adhesion. However, the biodegradation rate of these scaffolds based on a single material is uniform. Four-dimensional printing appears to be a promising method to control this aspect by changing the shape and/or the intrinsic properties of 3D-printed objects under the influence of external stimuli. Two main classes of biomaterials and biocomposites based on biopolyesters, namely poly(lactic acid) (PLA) and poly(caprolactone) (PCL), were used in this study. Each of them was mixed with the inorganic filler hydroxyapatite (HA), which is a component of natural bone. The biocomposites and biomaterials were prepared using the melt extrusion process and then shaped using a 3D printer. Three-dimensional specimens showed a decrease in elongation at break and breaking strain due to variations of crystallinity. The crystallinity of irradiated samples increased slightly with irradiation and a new crystalline phase was observed in the case of the PLA. Four-dimensional printing of biomaterials using electron radiation shows great promise for bone tissue engineering based on biocomposite scaffolds and other medical applications.
      Citation: Journal of Composites Science
      PubDate: 2021-07-10
      DOI: 10.3390/jcs5070182
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 183: Synthesis and Characterizations of
           Barium Zirconate–Alkali Carbonate Composite Electrolytes for
           Intermediate Temperature Fuel Cells

    • Authors: Gilles Taillades, Ismahan Hachemi, Paul Pers, Julian Dailly, Mathieu Marrony
      First page: 183
      Abstract: Composite ionic conductors for intermediate temperature fuel cells (ITFC) were produced by a combination of yttrium-substituted barium zirconate (BaZr0.9Y0.1 O2.95, BZY) and eutectic compositions of alkali carbonates (Li2CO3, Na2CO3, and K2CO3, abbreviated L, N, K). These materials were characterized by X-ray diffraction, scanning electron microscopy, and impedance spectroscopy. The combination of BZY with alkali metal carbonate promotes the densification and enhances the ionic conductivity, which reaches 87 mS·cm−1 at 400 °C for the BZY–LNK40 composite. In addition, the increase of the conductivity as a function of hydrogen partial pressure suggests that protons are the main charge carriers. The results are interpreted in terms of the transfer of protons from the ceramic component to the carbonate phase in the interfacial region.
      Citation: Journal of Composites Science
      PubDate: 2021-07-10
      DOI: 10.3390/jcs5070183
      Issue No: Vol. 5, No. 7 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 140: Controlled Magnetic Isolation and
           Decoupling of Perpendicular FePt Films by Capping Ultrathin Cu(002)
           Nano-Islands

    • Authors: Da-Hua Wei, Ji-Hong Chang, Chi-Chun Hsu, Cheng-Jie Yang, Yuan-Chang Liang, Chung-Li Dong, Yeong-Der Yao
      First page: 140
      Abstract: This study investigated the ultrathin Cu(002) capping nano-island effects on the magnetic characterizations and microstructure of epitaxial FePt(001) films directly fabricated on MgO(001) substrates at the relatively low temperature of 300 °C via electron-beam deposition. The enhancement of the coercivity is attributed to the lowered exchange coupling of FePt magnetic grains that begun from Cu atom behavior of spreading in many directions mainly along grain boundaries due to its lower surface energy than that of pure Fe or Pt. The measurement of angular-dependent coercivity shows a tendency of a domain-wall motion shift toward the rotation of the reverse-domain type upon the thickness of the Cu capping nano-island layer atop the FePt films. The intergranular interaction was clarified by the Kelly–Henkel plot, which indicated that there was strong exchange coupling (positive δM) between neighboring grains in the FePt continuous films without Cu capping nano-islands. On the other hand, a negative δM value was gained when the FePt films were capped with a Cu(002) single layer, indicating that the Cu capping layer can be used to control the strength of intergrain exchange coupling between the adjacent FePt grains and thicker Cu(002) capping nano-islands toward magnetic isolation; thus, there was an existence of dipole interaction in our designed Cu/FePt composite structure of stacked films.
      Citation: Journal of Composites Science
      PubDate: 2021-05-21
      DOI: 10.3390/jcs5060140
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 141: Dielectric Properties of Wood-Polymer
           Composites: Effects of Frequency, Fiber Nature, Proportion, and Chemical
           Composition

    • Authors: Imen Elloumi, Ahmed Koubaa, Wassim Kharrat, Chedly Bradai, Ahmed Elloumi
      First page: 141
      Abstract: The characterization of the dielectric properties of wood–polymer composites (WPCs) is essential to understand their interaction with electromagnetic fields and evaluate their potential use for new applications. Thus, dielectric spectroscopy monitored the evolution of the dielectric properties of WPCs over a wide frequency range of 1 MHz to 1 GHz. WPCs were prepared using mixtures of different proportions (40%, 50%, and 60%) of wood and bark fibers from various species, high-density polyethylene, and maleated polyethylene (3%) by a two-step process, extrusion and compression molding. Results indicated that wood fibers modify the resistivity of polyethylene at low frequencies but have no effect at microwave frequencies. Increasing the fiber content increases the composites’ dielectric properties. The fibers’ cellulose content explains the variation in the dielectric properties of composites reinforced with fibers from different wood species. Indeed, composites with high cellulose content show higher dielectric constants.
      Citation: Journal of Composites Science
      PubDate: 2021-05-24
      DOI: 10.3390/jcs5060141
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 142: Physico-Mechanical Study of
           CMC/BFO/PoPD Nanocomposite Films Reinforced with Cellulose Nanocrystals
           (CNCMCC) for Effective Photocatalytic Removal of Methyl Orange

    • Authors: Nurul Hidayu Nazri, Yogesh Kumar, Mohd Amirul Ramlan, Mohammad Haafiz Mohammad Kassim, Md. Sohrab Hossain, Noor Haida Mohd Kaus
      First page: 142
      Abstract: The present study was conducted to develop a nanocomposite film of carboxymethyl cellulose (CMC) reinforced with cellulose nanocrystals isolated from microcrystalline cellulose (CNCMCC) in the presence of bismuth ferrite (BFO)/poly-o-phenylenediamine (PoPD). The physicochemical properties, the mechanical and thermal stability, and its photocatalytic activity towards the removal of methyl orange (MO) were determined. Results show that the integration of CNCMCC into the CMC matrix enhanced the mechanical strength of the film. The tensile strength (TS) of the nanocomposite film increased from 0.205 to 0.244 MPa, while elongation at break (EB) decreased from 201.44 to 168.78% in the presence of 20 wt.% of CNCMCC. The incorporation of CNCMCC in the CMC matrix substantially enhanced the nanocomposite’s thermal stability from 181.16 to 185.59 °C and decreased the degradation residue from 72.64 to 63.16%. The determination of the photocatalytic activity of the CMC/CNCMCC/BFO/PoPD composite film revealed the removal of methyl orange (MO) of 93.64% with high structural integrity after 3 h of treatment. Thus, the isolated CNCMCC-reinforced CMC/BFO/PoPD composite film can be used as a photocatalyst for the removal of organic pollutants from wastewater, including the methyl orange.
      Citation: Journal of Composites Science
      PubDate: 2021-05-25
      DOI: 10.3390/jcs5060142
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 143: Practical Rubber Pre-Treatment Approch
           for Concrete Use—An Experimental Study

    • Authors: Rajeev Roychand, Rebecca J. Gravina, Yan Zhuge, Xing Ma, Julie E. Mills, Osama Youssf
      First page: 143
      Abstract: There is a lot of ongoing active research all over the world looking for various applications of used tyre rubber, to increase its utilisation rate. One of the common research applications is to incorporate rubber into concrete as a partial replacement for conventional aggregates. However, due to its poor bonding performance with cement paste, the utilisation of rubber in concrete has been hindered to date. A cost-effective and time-saving rubber pre-treatment method is of great interest, especially for the concrete industry. Out of all the various pre-treatment methods, soaking rubber particles in water is the most cost-effective and least complex method. In addition, sodium sulphate accelerates the hydration reaction of the cement composites. This study looks at the effect of soaking crumb rubber in tap water for short (2 h) and long (24 h) durations, and the optimised duration was then compared with soaking the crumb rubber in a 5% concentration of sodium sulphate solution. Compressive strength, bond behaviour, and rubber/cement interfacial transition zone (ITZ) were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. The results demonstrate that a soaking duration of 2 h provides much better performance in both the strength and bond properties compared to 24-h soaking. A further improvement in the 7-day strength was achieved with the rubber soaked in 5% sodium sulphate solution for 2 h, providing a more practical and economical rubber pre-treatment method for concrete industry use.
      Citation: Journal of Composites Science
      PubDate: 2021-05-26
      DOI: 10.3390/jcs5060143
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 144: The Performance of
           Filava-Polysiloxane, Silres® H62C Composite in High Temperature
           Application

    • Authors: Klaudio Bari, Thozhuvur Govindaraman Loganathan
      First page: 144
      Abstract: The research aim is to investigate the performance of novel enriched mineral fibres (Filava) in polysiloxane SLIRES H62 resin. Specimens were manufactured using a vacuum bagging process and oven cured at 250 °C. Specimens were prepared for flexural testing according to BS EN ISO 14125:1998 to obtain flexural strength, modulus, and elongation. The mechanical strength was compared to similar composites, with the aim of determining composite performance index. The flexural modulus (9.7 GPa), flexural strength (83 MPa), and flexural strain (2.9%) were obtained from a three-point bending test. In addition, the study investigates the thermal properties of the composite using a state-of-art Zwick Roell high temperature tensile rig. The results showed Filava/Polysiloxane Composites had an ultimate tensile strength 400 MPa, Young’s modulus 16 GPa and strain 2.5% at 1000 °C, and no smoke and ash were observed during pyrolysis. Ongoing research is currently taking place to use Filava-H62 in fire-retardant enclosure for lithium-ferro-phosphate Batteries used in electric trucks.
      Citation: Journal of Composites Science
      PubDate: 2021-05-27
      DOI: 10.3390/jcs5060144
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 145: Artificial Intelligence Application in
           Solid State Mg-Based Hydrogen Energy Storage

    • Authors: Song-Jeng Huang, Matoke Peter Mose, Sathiyalingam Kannaiyan
      First page: 145
      Abstract: The use of Mg-based compounds in solid-state hydrogen energy storage has a very high prospect due to its high potential, low-cost, and ease of availability. Today, solid-state hydrogen storage science is concerned with understanding the material behavior of different compositions and structure when interacting with hydrogen. Finding a suitable material has remained an elusive idea, and therefore, this review summarizes works by various groups, the milestones they have achieved, and the roadmap to be taken on the study of hydrogen storage using low-cost magnesium composites. Mg-based compounds are further examined from the perspective of artificial intelligence studies, which helps to improve prediction of their properties and hydrogen storage performance. There exist several techniques to improve the performance of Mg-based compounds: microstructure modification, use of catalytic additives, and composition regulation. Microstructure modification is usually achieved by employing different synthetic techniques like severe plastic deformation, high energy ball milling, and cold rolling, among others. These synthetic approaches are discussed herein. In this review, a discussion of key parameters and operating conditions are highlighted in a view to finding high storage capacity and faster kinetics. Furthermore, recent approaches like machine learning have found application in guiding the experimental design. Hence, this review paper also explores how machine learning techniques have been utilized to fasten the materials research. It is however noted that this study is not exhaustive in itself.
      Citation: Journal of Composites Science
      PubDate: 2021-05-29
      DOI: 10.3390/jcs5060145
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 146: Stress-Strain Behaviour and Mechanical
           Strengths of Concrete Incorporating Mixed Recycled Plastics

    • Authors: Mahmoud Abu-Saleem, Yan Zhuge, Reza Hassanli, Mark Ellis, Md Mizanur Rahman, Peter Levett
      First page: 146
      Abstract: Different types of recycled plastic have been used in concrete and most studies have focused on the behaviour of a single type of plastic. However, separating plastic wastes increases the cost and time of processing. To tackle this problem, this research presents an experimental investigation to determine the effect of incorporating different combinations of three types of recycled plastic waste aggregates—Polyethylene terephthalate (PET), High Density Polyethylene (HDPE) and Polypropylene (PP)—at different replacement ratios of coarse aggregate on physical and mechanical properties of concrete. The combinations include two plastic types at 10% and 20% replacement ratios and three plastic types at 15% and 30% replacement ratios. The performance of the plastic concrete was assessed based on various physical and mechanical properties including workability, fresh and dry densities, air content, compressive, indirect tensile and flexural strengths, modulus of elasticity, stress-strain behaviour and ultrasonic pulse velocity. It is found that the workability of Mixed Recycled Plastic Concrete (MRPC) at a low replacement rate is independent of the type of plastic. The minimum reduction in the compressive strength, indirect tensile and modulus of elasticity were achieved by R3 (PET + PP) at 10% replacement, while R5 (HDPE + PP) at 10% replacement achieved the highest flexural strength and ultrasonic pulse velocity values. The findings suggest that the mixed recycled plastics have a good possibility to partially replace coarse aggregates in concrete which will benefit the plastics recycling community and environment. Furthermore, the study will provide guidance to the concrete industry concerning the effect of the implementation of unsorted mixed types of plastic as coarse aggregates in the production of concrete.
      Citation: Journal of Composites Science
      PubDate: 2021-05-30
      DOI: 10.3390/jcs5060146
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 147: The Design of Carbon Fibre Composite
           Origami Airbrakes for Endeavour’s Darwin I Rocket

    • Authors: Hyeon (Ann) Lee, Parvez Alam
      First page: 147
      Abstract: This paper concerns the conceptual design of a carbon fibre composite airbrake intended for use on the Endeavour Darwin I rocket. The airbrake design is based on a Flasher origami model and we research its actuation mechanism, its ability to increase drag, and its mechanical behaviour when actuated. The aim of this work was to improve upon the current ‘Pancake’ airbrake model and we find that the origami Flasher generates six times more drag at a given torque. The Flasher is designed to be built of quasi-isotropic CFRP resting on a carbon fibre woven membrane. When subjected to distributed loads from drag, the Flasher presses into the membrane material causing it to stress at levels of 1.4 GPa. Taking into account a safety factor of 1.2 for the rocket airbrake, this stress lies far below the failure stress of the carbon fibre woven membrane. In this work, the composite Flasher origami airbrake design offers improvements in drag and weight reduction, and will withstand drag forces when actuated.
      Citation: Journal of Composites Science
      PubDate: 2021-06-01
      DOI: 10.3390/jcs5060147
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 148: Aligned Collagen-CNT Nanofibrils and
           the Modulation Effect on Ovarian Cancer Cells

    • Authors: Wen Li, Naiwei Chi, Elwin Clutter, Bofan Zhu, Rong Wang
      First page: 148
      Abstract: Fibrillar collagen is a one-dimensional biopolymer and is the most abundant structural protein in the extracellular matrix (ECM) of connective tissues. Due to the unique properties of carbon nanotubes (CNTs), considerable attention has been given to the application of CNTs in developing biocomposite materials for tissue engineering and drug delivery. When introduced to tissues, CNTs inevitably interact and integrate with collagen and impose a discernible effect on cells in the vicinity. The positive effect of the collagen-CNT (COL-CNT) matrix in tissue regeneration and the cytotoxicity of free CNTs have been investigated extensively. In this study, we aimed to examine the effect of COL-CNT on mediating the interaction between the matrix and SKOV3 ovarian cancer cells. We generated unidirectionally aligned collagen and COL-CNT nanofibrils, mimicking the structure and dimension of collagen fibrils in native tissues. AFM analysis revealed that the one-dimensional structure, high stiffness, and low adhesion of COL-CNT greatly facilitated the polarization of SKOV3 cells by regulating the β-1 integrin-mediated cell–matrix interaction, cytoskeleton rearrangement, and cell migration. Protein and gene level analyses implied that both collagen and COL-CNT matrices induced the epithelial–mesenchymal transition (EMT), and the COL-CNT matrix prompted a higher level of cell transformation. However, the induced cells expressed CD44 at a reduced level and MMP2 at an increased level, and they were responsive to the chemotherapy drug gemcitabine. The results suggested that the COL-CNT matrix induced the transdifferentiation of the epithelial cancer cells to mature, less aggressive, and less potent cells, which are inapt for tumor metastasis and chemoresistance. Thus, the presence of CNT in a collagen matrix is unlikely to cause an adverse effect on cancer patients if a controlled dose of CNT is used for drug delivery or tissue regeneration.
      Citation: Journal of Composites Science
      PubDate: 2021-06-02
      DOI: 10.3390/jcs5060148
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 149: Dental Bulk-Fill Resin Composites
           Polymerization Efficiency: A Systematic Review and Meta-Analysis

    • Authors: Reem Ajaj, Nada Farsi, Lama Alzain, Nour Nuwaylati, Raneem Ghurab, Hani Nassar
      First page: 149
      Abstract: Dental Bulk-Fill Composites (BFCs) and Bulk-Fill Flowables (BFFs) were introduced in the market to facilitate efficient bulk filling of cavities up to 5 mm. The aim of this study was to synthesize the literature investigating their polymerization efficiency. A comprehensive search of PubMed and the Cochrane Library from 2010 to January 2019 was performed using the medical subject headings. Screening of the titles, abstracts and full text was performed. Data extraction for relevant information was done on the included studies. Clinically relevant parameters were selected to present the study estimates (meta-analysis) using a random effects model for polymerization efficiency (Degree of Conversion (DC) and Depth of Cure (DoC)). Twenty one studies fulfilled the inclusion criteria and were included in the analysis reporting seven BFCs and nine BFFs. Ten materials reported acceptable DC values of above 55% and ten materials reported adequate DoC values. Most of the stated materials reported adequate DC and DoC values in at least one investigation with BFFs showing higher and more acceptable values compared to packable BFCs. It is suggested that future studies be carried out using a standard methodology following the ISO 4049 standard and manufacturer’s instructions to compare results.
      Citation: Journal of Composites Science
      PubDate: 2021-06-02
      DOI: 10.3390/jcs5060149
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 150: Numerical Simulation of the Forming
           Process of Veneer Laminates

    • Authors: David Zerbst, Christian Liebold, Thomas Gereke, Sebastian Clauß, Chokri Cherif
      First page: 150
      Abstract: In automotive manufacturing, laminated veneer sheets are formed to have 3D geometries for the production of trim parts with wood surfaces. Nowadays, investigation of the formability requires extensive tests with prototype tools, due to the brittle, anisotropic and inhomogeneous material behaviors. The present paper provides numerical methods for the simulation of the forming process of veneers with non-woven backings. Therefore, a conventional forming process of an interior trim part surface is carried out experimentally and numerically, using veneer samples with different individual textures originating from the characteristic growth ring structure. Gray scale images of these samples are mapped to finite element models to account for the wood-specific structure. The forming simulation process comprises two steps, where a gravity simulation depicts the initial position of the blank sheets and the closing of the tool induces the material deformation. The virtual forming of the digital twins accurately reproduces the wrinkling behavior observed in experimental studies. Based on the proposed methods, the design process of manufacturing wood trim parts based on tedious prototype tooling can be replaced by a fully virtual forming process taking into account the individual growth-related properties of the veneer structure.
      Citation: Journal of Composites Science
      PubDate: 2021-06-03
      DOI: 10.3390/jcs5060150
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 151: Study of the Physical Behavior of a
           New Composite Material Based on Fly Ash from the Combustion of Coal in an
           Ultra-Supercritical Thermal Power Plant

    • Authors: Mustapha El Kanzaoui, Chouaib Ennawaoui, Saleh Eladaoui, Abdelowahed Hajjaji, Abdellah Guenbour, Ratiba Boussen
      First page: 151
      Abstract: Given the amount of industrial waste produced and collected in the world today, a recycling and recovery process is needed. The study carried out on this subject focuses on the valorization of one of these industrial wastes, namely the fly ash produced by an ultra-supercritical coal power plant. This paper describes the use and recovery of fly ash as a high percentage reinforcement for the development of a new high-performance composite material for use in various fields. The raw material, fly ash, comes from the staged combustion of coal, which occurs in the furnace of an ultra-supercritical boiler of a coal-fired power plant. Mechanical compression, thermal conductivity, and erosion tests are used to study the mechanical, thermal, and erosion behavior of this new composite material. The mineralogical and textural analyses of samples were characterized using Scanning Electron Microscopy (SEM). SEM confirmed the formation of a new composite by a polymerization reaction. The results obtained are very remarkable, with a high Young’s modulus and a criterion of insulation, which approves the presence of a potential to be exploited in the different fields of materials. In conclusion, the composite material presented in this study has great potential for building material and could represent interesting candidates for the smart city.
      Citation: Journal of Composites Science
      PubDate: 2021-06-03
      DOI: 10.3390/jcs5060151
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 152: Impact Resistance of Fibre Reinforced
           Composite Railway Freight Tank Wagons

    • Authors: George Edward Street, Preetum Jayantilal Mistry, Michael Sylvester Johnson
      First page: 152
      Abstract: The use of fibre reinforced composite materials is one method by which the lightweighting of rail vehicles can be achieved. However, the issue of impact damage, amongst other challenges, limits their safety certification. This issue is accentuated by the high levels of loading a rail vehicle may be subjected to during service. This paper addresses the significance of pre-tension on large composite structures, specifically for a composite redesign of a pressure vessel for a freight tank wagon. Preloading was determined to be detrimental to the overall impact resistance of a large composite vessel. At 15.71 J of impact energy, there was a 22% increase in mean absorbed energy for a uniaxially loaded panel over an unloaded panel. However, there was only a 4% difference in penetration depth between uniaxial and biaxial loading. A novel finding from these results is that the effects of preloading are more profound if the loading does not act parallel to a principal fibre direction. Matrix cracking and delaminations are the most common failure modes observed for specimens under low-velocity impact and are intensified by preload.
      Citation: Journal of Composites Science
      PubDate: 2021-06-04
      DOI: 10.3390/jcs5060152
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 153: Study on the Melting Temperature, the
           Jumps of Volume, Enthalpy and Entropy at Melting Point, and the Debye
           Temperature for the BCC Defective and Perfect Interstitial Alloy WSi under
           Pressure

    • Authors: Hoc Nguyen Quang, Hien Nguyen Duc, Dung Nguyen Trong, Van Cao Long, Ştefan Ţălu
      First page: 153
      Abstract: The objective of this study is to determine the analytic expressions of the Helmholtz free energy, the equilibrium vacancy concentration, the melting temperature, the jumps of volume, enthalpy the mean nearest neighbor distance and entropy at melting point, the Debye temperature for the BCC defective, the limiting temperature of absolute stability for the crystalline state, and for the perfect binary interstitial alloy. The results obtained from the expressions are combined with the statistical moment method, the limiting condition of the absolute stability at the crystalline state, the Clausius–Clapeyron equation, the Debye model and the Gruneisen equation. Our numerical calculations of obtained theoretical results were carried out for alloy WSi under high temperature and pressure. Our calculated melting curve and relation between the melting temperature and the silicon concentration for WSi are in good agreement with other calculations. Our calculations for the jumps of volume, enthalpy and entropy, and the Debye temperature for WSi predict and orient experimental results in the future.
      Citation: Journal of Composites Science
      PubDate: 2021-06-07
      DOI: 10.3390/jcs5060153
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 154: Understanding the Coupling Effect
           between Lignin and Polybutadiene Elastomer

    • Authors: Sakrit Hait, Debapriya De, Prasenjit Ghosh, Jagannath Chanda, Rabindra Mukhopadhyay, Saikat Dasgupta, Aladdin Sallat, Muhannad Al Aiti, Klaus Werner Stöckelhuber, Sven Wießner, Gert Heinrich, Amit Das
      First page: 154
      Abstract: From an environmental and economic viewpoint, it is a win–win strategy to use materials obtained from renewable resources for the production of high-performance elastomer composites. Lignin, being a renewable biomass, was employed as a functional filler material to obtain an elastomer composite with a higher degree of mechanical performance. In the presence of a suitable coupling agent, an elevated temperature was preferred for the reactive mixing of lignin with polybutadiene rubber (BR). It is quite fascinating that the mechanical performance of this composite was comparable with carbon black-filled composites. The extraordinary reinforcing behavior of lignin in the BR matrix was understood by an available model of rubber reinforcement. In rubber composite preparation, the interfacial interaction between polybutadiene rubber and lignin in the presence of a coupling agent enabled the efficient dispersion of lignin into the rubber matrix, which is responsible for the excellent mechanical properties of the rubber composites. The rubber composites thus obtained may lead to the development of a sustainable and cost-effective end product with reliable performance. This novel approach could be implemented in other type of elastomeric materials, enabling a genuine pathway toward a sustainable globe.
      Citation: Journal of Composites Science
      PubDate: 2021-06-08
      DOI: 10.3390/jcs5060154
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 155: Development and Mechanical
           Characterisation of Al6061-Al2O3-Graphene Hybrid Metal Matrix Composites

    • Authors: Satish Babu Boppana, Samuel Dayanand, Bharath Vedashantha Murthy, Madeva Nagaral, Aravinda Telagu, Vijee Kumar, Virupaxi Auradi
      First page: 155
      Abstract: MMC based on aluminium (Al) were produced for light-weight applications especially in aviation and automobile areas. Present paper deals with the fabrication and mechanical performance of AA6061 matrix composites fortified with Al2O3 (alumina) and graphene particulates. Fluid metallurgy method namely stir casting route was employed for fabricating the hybrid composites. Al2O3p and graphene powder are mixed in different weight fractions in which graphene (1 wt. %) particle reinforcement is held consistent and Al2O3 reinforcement is differed freely with 5, 10 and 15 wt. %. Using optical analyser and SEM equipment, microstructural examination is carried out and the result reveals that the graphene and Al2O3 particles prevalently are homogeneously appropriated on the grain limits of Al matrix and Al2O3 particles are disseminated between graphene in the as-cast AA6061 MMC’s. Detailed analysis on investigation of the microstructure and mechanical aspects of Al6061-graphene-Al2O3p composites is presented by following ASTM guidelines; results uncovered that with increment in reinforcement particles, there is an enhancement in the hardness, ultimate strength, yield strength and a decline in the elongation values was however noticed when contrasted with Al6061 alloy. Fractography investigation revealed dimples in unreinforced alloy and the composite.
      Citation: Journal of Composites Science
      PubDate: 2021-06-10
      DOI: 10.3390/jcs5060155
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 156: Impact of Fly Ash on Time-Dependent
           Properties of Agro-Waste Lightweight Aggregate Concrete

    • Authors: Mehdi Maghfouri, Vahid Alimohammadi, Pejman Azarsa, Iman Asadi, Yashar Doroudi, Balamohan Balakrishnan
      First page: 156
      Abstract: The utilization of by-products and waste materials to substitute for the natural or manufactured resources is considered as a practical way to obtain green building materials. In concrete mixtures, amongst the many available options, Fly Ash (FA) as a by-product pozzolan has been used as a partial replacement of cement. As for the aggregates, lightweight agro-waste oil palm shell (OPS) can be used as a replacement to conventional aggregate for the production of lightweight aggregate concrete. The present communication aims to investigate the impact of FA on time-dependent development properties of OPS lightweight aggregate concrete, including density, water absorption, compressive strength up to 120-days, and drying shrinkage up to the age of 365-days under standard moist curing, partially early curing, and non-curing conditions. Additionally, drying shrinkage crack development was investigated. In this study, two series of concrete mixtures with different substitution levels of OPS (0%, 50%, and 100%) and FA were tested. From the obtained results, it was concluded that the incorporation of fly ash in OPS concrete reduces the density and compressive strength values. Dually, the initial and final water absorption values plus the rate of drying shrinkage at early and long-term ages increased. On top of that, a high potential of drying shrinkage crack, especially for mixtures with 100% OPS, was identified.
      Citation: Journal of Composites Science
      PubDate: 2021-06-10
      DOI: 10.3390/jcs5060156
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 157: A Multi-Scale Method for Designing
           Hybrid Fiber-Reinforced Composite Drive Shafts with Carbon Nanotube
           Inclusions

    • Authors: Stelios K. Georgantzinos, Panagiotis A. Antoniou, Stylianos I. Markolefas
      First page: 157
      Abstract: In this paper, the modal and linear buckling analysis of a laminated composite drive shaft reinforced by 11 multi-walled carbon nanotubes (MWCNTs) was carried out using an analytical approach, as well as the finite element method (FEM). The theoretical model is based on classical laminated theory (CLT). The fundamental frequency and the critical buckling torque were determined for different fiber orientation angles. The Halpin–Tsai model was employed to calculate the elastic modulus of composites having randomly oriented nanotubes. The effect of various carbon nanotube (CNT) volume fractions in the epoxy resin matrix on the material properties of unidirectional composite laminas was also analyzed. The fundamental frequency and the critical buckling torque obtained by the finite element analysis and the analytical method for different fiber orientation angles were in good agreement with each other. The results were verified with data available in the open literature, where possible. For the first time in the literature, the influence of CNT fillers on various composite drive shaft design parameters such as the fundamental frequency, critical speed, and critical buckling torque of a hybrid fiber-reinforced composite drive shaft is finally predicted.
      Citation: Journal of Composites Science
      PubDate: 2021-06-10
      DOI: 10.3390/jcs5060157
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 158: Chromatic Conductive Polymer
           Nanocomposites of Poly (p-Phenylene Ethynylene)s and Single-Walled Carbon
           Nanotubes

    • Authors: Shanju Zhang, Uwe H. F. Bunz, David G. Bucknall
      First page: 158
      Abstract: We report on dispersions and thin films of chromatic conductive nanocomposites of poly(p-phenylene ethynylene)s (PPEs) and single-walled carbon nanotubes (SWNTs) generated via solution mixing. The linear, conjugated PPEs with dialkyl- and dialkyloxy-side chain groups are shown to debundle and disperse high concentration (up to 2.5 mg/mL) SWNTs in various organic solvents. The solubilization of SWNTs and PPE wrapping is accompanied with the change in the solution color. Ultraviolet visible absorption spectra of nanocomposite solutions demonstrate a new absorption peak at a higher wavelength, supporting the observed chromatism. Fluorescence spectra of nanocomposite solutions display significant quenching of the fluorescence intensity and the Stern–Volmer model is used to analyze fluorescence quenching. Electron microscopy of the chromatic solid films of high mass fraction PPE/SWNT nanocomposites obtained by vacuum filtration reveals the debundled SWNTs in the PPE matrix. The tensile strength and Young’s modulus of these PPE/SWNT nanocomposite films are as high as 150 MPa and 15 GPa, respectively. The composite films exhibit remarkably high conductivities, ranging from ~1000 S/m to ~10,000 S/m for 10 wt% and 60 wt% SWNT nanocomposites, respectively.
      Citation: Journal of Composites Science
      PubDate: 2021-06-14
      DOI: 10.3390/jcs5060158
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 159: Overmoulding of Additively
           Manufactured Titanium Inserts Using Polyoxymethylene (POM)—Evaluation of
           Bond Quality as a Function of Process Parameters

    • Authors: Teresa Liese, Julia Richter, Thomas Niendorf, Angela Ries
      First page: 159
      Abstract: Due to their process-induced porous surfaces, additively manufactured structures are not optimized for applications in which friction is a key factor. To improve the frictional properties of additively manufactured titanium inserts of various thicknesses, two tribologically optimized POM materials, which differ in terms of filler composition and contents, were used to overmould the inserts. The titanium inserts were manufactured in two different building directions, resulting in a variation in surface roughness. The main challenge with respect to overmoulding is to maintain an even, thin plastic layer on the titanium insert. In order to evaluate the adhesion between plastic and metal, the interface is examined by optical microscopy and assessment of the peeling resistance. The peeling test shows that the overmoulded titanium inserts with a higher surface roughness are characterized by a higher peeling resistance. It is further revealed that the POM material with a special filler concept shows superior peeling resistance.
      Citation: Journal of Composites Science
      PubDate: 2021-06-15
      DOI: 10.3390/jcs5060159
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 160: An Overview of the Design of
           Chitosan-Based Fiber Composite Materials

    • Authors: Chen Xue, Lee D. Wilson
      First page: 160
      Abstract: Chitosan composite fibrous materials continue to generate significant interest for wastewater treatment, food packaging, and biomedical applications. This relates to the relatively high surface area and porosity of such fibrous chitosan materials that synergize with their unique physicochemical properties. Various methods are involved in the preparation of chitosan composite fibrous materials, which include the modification of the biopolymer that serve to alter the solubility of chitosan, along with post-treatment of the composite materials to improve the water stability or to achieve tailored functional properties. Two promising methods to produce such composite fibrous materials involve freeze-drying and electrospinning. Future developments of such composite fibrous materials demands an understanding of the various modes of preparation and methods of structural characterization of such materials. This review contributes to an understanding of the structure–property relationships of composite fibrous materials that contain chitosan, along with an overview of recent advancements concerning their preparation.
      Citation: Journal of Composites Science
      PubDate: 2021-06-17
      DOI: 10.3390/jcs5060160
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 161: Mathematical Simulation of the
           Wettability of Al2O3 Substrate through Different Aluminum Alloys

    • Authors: Enrique Rocha-Rangel, José A. Rodríguez-García, José A. Castillo-Robles, Eddie N. Armendáriz Mireles, Carlos A. Calles-Arriaga
      First page: 161
      Abstract: The wetting process of a ceramic substrate (Al2O3) with and without carbon coating by means of aluminum-based alloys has been investigated. A mathematical simulation that predicts wettability in the systems under study is proposed, taking into account the diffusional effects of the used constituents. The prediction of the mathematical simulation is compared with the experimental results obtained for the same systems in question. From the results obtained, it was found that the wettability of a liquid droplet of aluminum and aluminum alloys on an alumina (Al2O3) substrate with and without carbon coating can be well represented by the proposed mathematical diffusion simulation. On the other hand, the control mechanism of the contact angle in relation to the deposition of a thin layer of carbon on the ceramic substrate (Al2O3) and the presence of metals such as La and Y in the aluminum alloy, give way to the formation of Al4C3, La2O3 and Y2O3 and these types of reaction help in the decrease of the contact angle.
      Citation: Journal of Composites Science
      PubDate: 2021-06-20
      DOI: 10.3390/jcs5060161
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 162: A Comprehensive Review of Polymeric
           Wastewater Purification Membranes

    • Authors: Rasmeet Singh, Mandeep Singh, Nisha Kumari, Janak, Sthitapragyan Maharana, Pragyansu Maharana
      First page: 162
      Abstract: Synthetic membranes are currently employed for multiple separation applications in various industries. They may have been prepared from organic or inorganic materials. Present research majorly focuses on polymeric (i.e., organic) membranes because they show better flexibility, pore formation mechanism, and thermal and chemical stability, and demand less area for installation. Dendritic, carbon nanotube, graphene and graphene oxide, metal and metal oxide, zwitter-ionic, and zeolite-based membranes are among the most promised water treatment membranes. This paper critically reviews the ongoing developments to utilize nanocomposite membranes to purify water. Various membranes have been reported to study their resistance and fouling properties. A special focus is given towards multiple ways in which these nanocomposite membranes can be employed. Therefore, this review provides a platform to develop the awareness of current research and motivate its readers to make further progress for utilizing nanocomposite membranes in water purification.
      Citation: Journal of Composites Science
      PubDate: 2021-06-21
      DOI: 10.3390/jcs5060162
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 163: Study of the Effect of the A206/1.0
           wt. % γAl2O3 Nanocomposites Content on the Portevin-Le Chatelier
           Phenomenon in Al/0.5 wt. % Mg Alloys

    • Authors: David Florián-Algarín, Xiaochun Li, Hongseok Choi, Oscar Marcelo Suárez
      First page: 163
      Abstract: The Portevin-Le Chatelier (PLC) phenomenon or dynamic strain aging in Al–0.5 wt. % Mg alloys was investigated at different strain rates. This research also examined the effect of γAl2O3 nanoparticles on the PLC phenomenon. A nanocomposite made of A206/1.0 wt. % γAl2O3 was manufactured to this purpose and then, added to an Al–0.5 wt. % Mg melt to obtain ingots of Al–0.5 wt. % Mg–20 wt. % A206/1.0 wt. % γAl2O3 and Al–0.5 wt. % Mg–10 wt. % A206/1.0 wt. % γAl2O3 with 6 mm diameter. Cold deformation allowed manufacturing 1 mm diameter wires using the 6 mm diameter ingots. A 300 °C solution treatment, followed by rapid cooling in ice water permitted to retain Mg atoms in solid solution. The tensile tests performed on the wires revealed the PLC phenomenon upon the tensile stress vs. strain plastic zone. The phenomenon was quantified using MatLab™ and statistical analysis. The results demonstrated how the alumina nanoparticles can diminish the serration amplitude of the PLC phenomenon.
      Citation: Journal of Composites Science
      PubDate: 2021-06-21
      DOI: 10.3390/jcs5060163
      Issue No: Vol. 5, No. 6 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 115: Ballistic Impact and Virtual Testing
           of Woven FRP Laminates

    • Authors: Ioannis K. Giannopoulos, Mehdi Yasaee, Nikolaos Maropakis
      First page: 115
      Abstract: The aim of the work was to investigate the numerical simulations correlation with the experimental behaviour of steel ball high velocity impact onto a 2 × 2 twill woven carbon composite laminate. The experimental set up consisted of a pressurised gas-gun able to shot steel ball projectiles onto two different composite plate layup configurations of plates made of the same composite material fabric. Subsequently, the experiments were replicated using the LSDYNA explicit finite element analysis software package. Progressive failure numerical models of two different fidelity levels were constructed. The higher fidelity model was simulating each of the plys of the composite panels separately, tied together using cohesive zone modelling properties. The lower fidelity model consisted of a single layer plate with artificial integration points for each ply. The simulation results came out to be in satisfactory agreement with the experimental ones. While the delamination extent was moderately under predicted by the higher fidelity model, the general behaviour was complying with the experimental results. The lower fidelity model was consistent in representing the damage of the panel during the impact and better predicted the impactor residual velocities due to the better matching of the pane stiffness. Despite the competency of the higher fidelity model to capture the damage of the laminate in a more detailed level, the computational cost was 80% higher than the lower fidelity case, which rendered that model impractical against the lower fidelity one, to use in larger models representing more substantial or more complex structures.
      Citation: Journal of Composites Science
      PubDate: 2021-04-22
      DOI: 10.3390/jcs5050115
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 116: Numerical Buckling Analysis of Hybrid
           Honeycomb Cores for Advanced Helmholtz Resonator Liners

    • Authors: Moritz Neubauer, Martin Dannemann, Michael Kucher, Niklas Bleil, Tino Wollmann, Niels Modler
      First page: 116
      Abstract: In order to realize novel acoustic liners, honeycomb core structures specially adapted to these applications are required. For this purpose, various design concepts were developed to create a hybrid cell core by combining flexible wall areas based on thermoplastic elastomer films and rigid honeycomb areas made of fiber-reinforced thermoplastics. Within the scope of the presented study, a numerical approach was introduced to analyze the global compressive failure of the hybrid composite core structure, considering local buckling and composite failure according to Puck and Cuntze. Therefore, different geometrical configurations of fiber-reinforced tapes were compared with respect to their deformation as well as their resulting failure behavior by means of a finite element analysis. The resulting compression strength obtained by a linear buckling analysis agrees largely with calculated strengths of the more elaborate application of the failure criteria according to Puck and Cuntze, which were implemented in the framework of a nonlinear buckling analysis. The findings of this study serve as a starting point for the realization of the manufacturing concept, for the design of experimental tests of hybrid composite honeycomb core structures, and for further numerical investigations considering manufacturing as well as material specific aspects.
      Citation: Journal of Composites Science
      PubDate: 2021-04-23
      DOI: 10.3390/jcs5050116
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 117: Optimization of Operating Conditions
           for Electrochemical Decolorization of Methylene Blue with
           Ti/α-PbO2/β-PbO2 Composite Electrode

    • Authors: Md. Ashraful Islam Molla, Genta Yanagi, Mai Furukawa, Ikki Tateishi, Hideyuki Katsumata, Satoshi Kaneco
      First page: 117
      Abstract: α-PbO2 was introduced into the intermediate layer of an electrode to prevent the separation of the electrodeposited layer and maintain oxidizing power. The resulting Ti/α-PbO2/β-PbO2 composite electrode was applied to the electrochemical decolorization of methylene blue (MB) and the operating conditions for MB decolorization with the Ti/α-PbO2/β-PbO2 electrode were optimized. The morphology, structure, composition, and electrochemical performance of Ti/α-PbO2 and Ti/α-PbO2/β-PbO2 anode were evaluated using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The optimum operating parameters for the electrochemical decolorization of MB at Ti/α-PbO2/β-PbO2 composites were as follows: Na2SO4 electrolyte 0.05 g L−1, initial concentration of MB 9 mg L−1, cell voltage 20 V, current density 0.05–0.10 A cm−2, and pH 6.0. MB dye could be completely decolorized with Ti/α-PbO2/β-PbO2 for the treatment time of less than one hour, and the dye decolorization efficiency with Ti/α-PbO2/β-PbO2 was about 5 times better, compared with those obtained with Ti/α-PbO2.
      Citation: Journal of Composites Science
      PubDate: 2021-04-27
      DOI: 10.3390/jcs5050117
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 118: Structural Optimization of Locally
           Continuous Fiber-Reinforcements for Short Fiber-Reinforced Plastics

    • Authors: Konstantin Mehl, Sebastian Schmeer, Nicole Motsch-Eichmann, Philipp Bauer, Ingolf Müller, Joachim Hausmann
      First page: 118
      Abstract: The integration of continuous fiber-reinforced structures into short or long fiber-reinforced plastics allows a significant increase in stiffness and strength. In order to make the best possible use of the high stiffness and strength of continuous fiber-reinforcements, they must be placed in the direction of load in the most stressed areas. A frequently used tool for identifying the most heavily loaded areas is topology optimization. Commercial topology optimization programs usually do not take into account the material properties associated with continuous fiber-reinforced hybrid structures. The anisotropy of the reinforcing material and the stiffness of the base material surrounding the reinforcement are not considered during topology optimization, but only in subsequent steps. Therefore in this publication, existing optimization methods for hybrid and anisotropic materials are combined to a new approach, which takes into account both the anisotropy of the continuous fiber-reinforcement and the stiffness of the base material. The results of the example calculations not only show an increased stiffness at the same material input but also a simplification of the resulting reinforcement structures, which allows more economical manufacturing.
      Citation: Journal of Composites Science
      PubDate: 2021-04-27
      DOI: 10.3390/jcs5050118
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 119: Additive Manufacturing for Effective
           Smart Structures: The Idea of 6D Printing

    • Authors: Stelios K. Georgantzinos, Georgios I. Giannopoulos, Panteleimon A. Bakalis
      First page: 119
      Abstract: This paper aims to establish six-dimensional (6D) printing as a new branch of additive manufacturing investigating its benefits, advantages as well as possible limitations concerning the design and manufacturing of effective smart structures. The concept of 6D printing, to the authors’ best knowledge, is introduced for the first time. The new method combines the four-dimensional (4D) and five-dimensional (5D) printing techniques. This means that the printing process is going to use five degrees of freedom for creating the final object while the final produced material component will be a smart/intelligent one (i.e., will be capable of changing its shape or properties due to its interaction with an environmental stimulus). A 6D printed structure can be stronger and more effective than a corresponding 4D printed structure, can be manufactured using less material, can perform movements by being exposed to an external stimulus through an interaction mechanism, and it may learn how to reconfigure itself suitably, based on predictions via mathematical modeling and simulations.
      Citation: Journal of Composites Science
      PubDate: 2021-05-01
      DOI: 10.3390/jcs5050119
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 120: Development of a Pultrusion Die for
           the Production of Thermoplastic Composite Filaments to Be Used in Additive
           Manufacture

    • Authors: Filipe Ferreira, Pedro Fernandes, Nuno Correia, António Torres Marques
      First page: 120
      Abstract: The use of 3D printing has proven to have significant benefits to manufacture components with complex geometries with several types of materials and reinforcements for a wide variety of uses including structural applications. The focus of this study is to develop and implement a thermoplastic pultrusion process that can obtain a carbon fiber/polypropylene (CF/PP) filament for a 3D printing process. This development process included the design and finite element analysis of the die used to conform the filament, considering the adaptation of a filament-winding setup to achieve adequate production conditions. The finite element model tried to achieve homogeneous heating of the die with the use of a series of resistors controlled by PID controllers monitoring several thermocouples strategically positioned while the use of water circulating channels was responsible for the cooling effect. The die-heating environment is optimized for different scenarios with different initial temperatures, cooling temperatures, and pulling speeds. A series of experiments were performed under different conditions, such as different heating temperatures and pulling speeds to analyze the quality of the filament produced. The obtained filaments presented an average diameter of 1.94 mm, fiber volume fraction of 43.76%, and void content of 6.97%.
      Citation: Journal of Composites Science
      PubDate: 2021-05-01
      DOI: 10.3390/jcs5050120
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 121: 3D X-ray Microscopy as a Tool for in
           Depth Analysis of the Interfacial Interaction between a Single Carbon
           Fiber and an Epoxy Matrix after Mechanical Loading

    • Authors: Vogtmann, Klingler, Rief, Gurka
      First page: 121
      Abstract: The benefit of fiber-reinforced composites originates from the interaction between the fiber reinforcement and the matrix. This interplay controls many of its mechanical properties and is of utmost importance to enable its unique performance as a lightweight material. However, measuring the fiber−matrix interphase strength with micromechanical tests, like the Broutman test, is challenging, due to the many, often unknown boundary conditions. Therefore, this study uses state-of-the-art, high-resolution X-ray computed microtomography (XRM) as a tool to investigate post mortem the failure mechanisms of single carbon fibers within an epoxy matrix. This was conducted at the example of single carbon fiber Broutman test specimens. The capabilities of today’s XRM analysis were shown in comparison to classically obtained light microscopy. A simple finite element model was used to enhance the understanding of the observed fracture patterns. In total, this research reveals the possibilities and limitations of XRM to visualize and assess compression-induced single fiber fracture patterns. Furthermore, comparing two different matrix systems with each other illustrates that the failure mechanisms originate from differences in the fiber−matrix interphases. The carbon fiber seems to fail due to brittleness under compression stress. Observation of the fiber slippage and deformed small fracture pieces between the fragments suggests a nonzero stress state at the fragment ends after fiber failure. Even more, these results demonstrate the usefulness of XRM as an additional tool for the characterization of the fiber−matrix interphase.
      Citation: Journal of Composites Science
      PubDate: 2021-05-04
      DOI: 10.3390/jcs5050121
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 122: Self-Healing Potential and
           Post-Cracking Tensile Behavior of Polypropylene Fiber-Reinforced
           Cementitious Composites

    • Authors: Mohit Garg, Pejman Azarsa, Rishi Gupta
      First page: 122
      Abstract: The use of synthetic fibers as reinforcement in fiber-reinforced cementitious composites (FRCC) demonstrates a combination of better ductile response vis-à-vis metallic ones, enhanced durability in a high pH environment, and resistance to corrosion as well as self-healing capabilities. This study explores the effect of macro- and micro-scale polypropylene (PP) fibers on post-crack energy, ductility, and the self-healing potential of FRCC. Laboratory results indicate a significant change in fracture response, i.e., loss in ductility as curing time increases. PP fiber samples cured for 2 days demonstrated ductile fracture behavior, controllable crack growth during tensile testing, post-cracking behavior, and a regain in strength owing to FRCC’s self-healing mechanism. Different mixes of FRCC suggest an economical mixing methodology, where the strong bond between the PP fibers and cementitious matrix plays a key role in improving the tensile strength of the mortar. Additionally, the micro PP fiber samples demonstrate resistance to micro-crack propagation, observed as an increase in peak load value and shape deformation during compression and tensile tests. Notably, low volume fraction of macro-scale PP fibers in FRCC revealed higher post-crack energy than the higher dosage of micro-scale PP fibers. Lastly, few samples with a crack of < 0.5 mm exhibited a self-healing mechanism, and upon testing, the healed specimens illustrated higher strain values.
      Citation: Journal of Composites Science
      PubDate: 2021-05-07
      DOI: 10.3390/jcs5050122
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 123: The Biomimetic Evolution of Composite
           

    • Authors: Gad Marom
      First page: 123
      Abstract: Advanced polymer-based composite materials have revolutionized the structural material arena since their appearance some 60 years ago. Yet, despite their relatively short existence, they seem to be taken for granted as if they have always been there. One of the reasons for this state of affairs is that composite materials of various types have accompanied human history for thousands years, and their emergence in the modern era could be considered a natural evolutionary process. Nevertheless, the continuous line that leads from early days of composites in human history to current structural materials has exhibited a number of notable steps, each generating an abrupt advance toward the contemporary new science of composite materials. In this paper, I review and discuss the history of composites with emphasis on the main steps of their development.
      Citation: Journal of Composites Science
      PubDate: 2021-05-07
      DOI: 10.3390/jcs5050123
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 124: Kinetic Analysis on the Stabilization
           Effects of Substituted POSS Powders Embedded in γ-Radiolyzed
           Polypropylene

    • Authors: Traian Zaharescu, Ignazio Blanco, Tunde Borbath, Istvan Borbath, Marius Mariș
      First page: 124
      Abstract: The present paper proposes a reliable alternative for the increasing stability of polypropylene (PP) by modified polyhedral oligomeric silsesquioxanes (POSS). The chemiluminescence measurements and FTIR records point complementarily out the determinant influence of substituents on the progress of oxidation during the accelerated degradation caused by γ-irradiation. The main kinetic approach of oxidation acting in radiation-induced aging recommends some of the studied structures of modified POSS as appropriate compounds for improving stability of polypropylene at low additive concentration. The analysis of the present results is based on the implication of substituted POSS, whose contribution to the limitation of oxidation is conditioned by the influence of substituents. The delay of the oxidative degradation in studied γ-irradiated polypropylene is the consequence of the interaction between molecular PP fragments and the silanol moieties generated during radiolysis, which are the most vulnerable points of POSS structure.
      Citation: Journal of Composites Science
      PubDate: 2021-05-09
      DOI: 10.3390/jcs5050124
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 125: A Green Composite Based on
           Gelatin/Agarose/Zeolite as a Potential Scaffold for Tissue Engineering
           Applications

    • Authors: Mohamadreza Youssefi Azarfam, Mojtaba Nasirinezhad, Haleh Naeim, Payam Zarrintaj, Mohammadreza Saeb
      First page: 125
      Abstract: Designing a novel platform capable of providing a proper tissue regeneration environment is a key factor in tissue engineering. Herein, a green composite based on gelatin/agarose/zeolite with pomegranate peel extract was fabricated as an innovative platform for tissue engineering. Gelatin/agarose was loaded with pomegranate peel extract-loaded zeolite to evaluate its swelling behavior, porosity, release rate, and cell viability performance. The composite characteristics were evaluated using XRD and DSC. The hydrogel performance can be adjusted for the desired aim by zeolite content manipulation, such as controlled release. It was shown that the green nanocomposite exhibited proper cellular activity along with a controlled release rate. Moreover, the hydrogel composite’s swelling ratio was decreased by adding zeolite. This study suggested a fully natural composite as a potential biomaterial for tissue engineering, which opens new ways to design versatile hydrogels for the regeneration of damaged tissues. The hydrogel performance can be adjusted specifically by zeolite content manipulation for controlled release.
      Citation: Journal of Composites Science
      PubDate: 2021-05-09
      DOI: 10.3390/jcs5050125
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 126: Study of the Surface and Dimensional
           Quality of the AlSi10Mg Thin-Wall Components Manufactured by Selective
           Laser Melting

    • Authors: Muhammad Waqas, Dingyong He, Hassan Elahi, Saleem Riaz, Marco Eugeni, Paolo Gaudenzi
      First page: 126
      Abstract: Additive manufacturing (AM), a 3D printing technique that manufactures components by sequential addition of powder, has massively reshaped the manufacturing and engineering sectors from batch production to manufacturing customized, innovative, state-of-the-art, and sustainable products. Additive manufacturing of aluminum alloys by selective laser melting (SLM) is one of the latest research trends in this field due to the fact of its advantages and vast applications in manufacturing industries such as automobiles and aerospace. This paper investigated the surface and dimensional quality of SLM-built AlSi10Mg parts using a response surface method (RSM) and found the influence of the wall thickness and process parameters (i.e., laser power, scanning speed, hatch distance) on the pieces. Thin-walled test specimens of AlSi10Mg alloy were manufactured with different combinations of process parameters at three wall thicknesses: 1.0 mm, 2.0 mm, and 3.0 mm. The Minitab DOE module was used to create 27 different configurations of wall thickness and process parameters. The samples’ surface roughness and dimensional accuracy were investigated, and the findings were evaluated using the ANOVA technique. The regression model and the ANOVA technique showed high precision and had a particular reference value for practical engineering applications.
      Citation: Journal of Composites Science
      PubDate: 2021-05-09
      DOI: 10.3390/jcs5050126
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 127: Compounding of Short Fiber Reinforced
           Phenolic Resin by Using Specific Mechanical Energy Input as a Process
           Control Parameter

    • Authors: Robert Maertens, Wilfried V. Liebig, Peter Elsner, Kay A. Weidenmann
      First page: 127
      Abstract: For a newly developed thermoset injection molding process, glass fiber-reinforced phenolic molding compounds with fiber contents between 0 wt% and 60 wt% were compounded. To achieve a comparable remaining heat of the reaction in all compound formulations, the specific mechanical energy input (SME) during the twin-screw extruder compounding process was used as a control parameter. By adjusting the extruder screw speed and the material throughput, a constant SME into the resin was targeted. Validation measurements using differential scanning calorimetry showed that the remaining heat of the reaction was higher for the molding compounds with low glass fiber contents. It was concluded that the SME was not the only influencing factor on the resin crosslinking progress during the compounding. The material temperature and the residence time changed with the screw speed and throughput, and most likely influenced the curing. However, the SME was one of the major influence factors, and can serve as an at-line control parameter for reactive compounding processes. The mechanical characterization of the test specimens revealed a linear improvement in tensile strength up to a fiber content of 40–50 wt%. The unnotched Charpy impact strength at a 0° orientation reached a plateau at fiber fractions of approximately 45 wt%.
      Citation: Journal of Composites Science
      PubDate: 2021-05-11
      DOI: 10.3390/jcs5050127
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 128: Parametric Optimization of Isotropic
           and Composite Axially Symmetric Shells Subjected to External Pressure and
           Twisting

    • Authors: Marek Barski, Paweł J. Romanowicz, Małgorzata Chwał, Adam Stawiarski
      First page: 128
      Abstract: The present paper is devoted to the problem of the optimal design of thin-walled composite axially symmetric shells with respect to buckling resistance. The optimization problem is formulated with the following constraints: namely, all analyzed shells have identical capacity and volume of material. The optimization procedure consists of four steps. In the first step, the initial calculations are made for cylindrical shells with non-optimal orientation of layers and these results are used as the reference for optimization. Next, the optimal orientations of layers for cylindrical shapes are determined. In the third step, the optimal geometrical shape of a middle surface with a constant thickness is determined for isotropic material. Finally, for the assumed shape of the middle surface, the optimal fiber orientation angle θ of the composite shell is appointed. Such studies were carried for three cases: pure external pressure, pure twisting, and combined external pressure with twisting. In the case of shells made of isotropic material the obtained results are compared with the optimal structure of uniform stability, where the analytical Shirshov’s local stability condition is utilized. In the case of structures made of composite materials, the computations are carried out for two different materials, where the ratio of E1/E2 is equal to 17.573 and 3.415. The obtained benefit from optimization, measured as the ratio of critical load multiplier computed for reference shell and optimal structure, is significant. Finally, the optimal geometrical shapes and orientations of the layers for the assumed loadings is proposed.
      Citation: Journal of Composites Science
      PubDate: 2021-05-12
      DOI: 10.3390/jcs5050128
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 129: A Hierarchical Architecture of
           Functionalized Polyaniline/Manganese Dioxide Composite with
           Stable-Enhanced Electrochemical Performance

    • Authors: Yapeng Wang, Yanxiang Wang, Chengjuan Wang, Yongbo Wang
      First page: 129
      Abstract: As one of the most outstanding high-efficiency and environmentally friendly energy storage devices, the supercapacitor has received extensive attention across the world. As a member of transition metal oxides widely used in electrode materials, manganese dioxide (MnO2) has a huge development potential due to its excellent theoretical capacitance value and large electrochemical window. In this paper, MnO2 was prepared at different temperatures by a liquid phase precipitation method, and polyaniline/manganese dioxide (PANI/MnO2) composite materials were further prepared in a MnO2 suspension. MnO2 and PANI/MnO2 synthesized at a temperature of 40 °C exhibit the best electrochemical performance. The specific capacitance of the sample MnO2-40 is 254.9 F/g at a scanning speed of 5 mV/s and the specific capacitance is 241.6 F/g at a current density of 1 A/g. The specific capacitance value of the sample PANI/MnO2-40 is 323.7 F/g at a scanning speed of 5 mV/s, and the specific capacitance is 291.7 F/g at a current density of 1 A/g, and both of them are higher than the specific capacitance value of MnO2. This is because the δ-MnO2 synthesized at 40 °C has a layered structure, which has a large specific surface area and can accommodate enough electrolyte ions to participate the electrochemical reaction, thus providing sufficient specific capacitance.
      Citation: Journal of Composites Science
      PubDate: 2021-05-13
      DOI: 10.3390/jcs5050129
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 130: A Review on Mechanical Properties of
           Natural Fibre Reinforced Polymer Composites under Various Strain Rates

    • Authors: Tan Ke Khieng, Sujan Debnath, Ernest Ting Chaw Liang, Mahmood Anwar, Alokesh Pramanik, Animesh Kumar Basak
      First page: 130
      Abstract: With the lightning speed of technological evolution, the demand for high performance yet sustainable natural fibres reinforced polymer composites (NFPCs) are rising. Especially a mechanically competent NFPCs under various loading conditions are growing day by day. However, the polymers mechanical properties are strain-rate dependent due to their viscoelastic nature. Especially for natural fibre reinforced polymer composites (NFPCs) which the involvement of filler has caused rather complex failure mechanisms under different strain rates. Moreover, some uneven micro-sized natural fibres such as bagasse, coir and wood were found often resulting in micro-cracks and voids formation in composites. This paper provides an overview of recent research on the mechanical properties of NFPCs under various loading conditions-different form (tensile, compression, bending) and different strain rates. The literature on characterisation techniques toward different strain rates, composite failure behaviours and current challenges are summarised which have led to the notion of future study trend. The strength of NFPCs is generally found grow proportionally with the strain rate up to a certain degree depending on the fibre-matrix stress-transfer efficiency. The failure modes such as embrittlement and fibre-matrix debonding were often encountered at higher strain rates. The natural filler properties, amount, sizes and polymer matrix types are found to be few key factors affecting the performances of composites under various strain rates whereby optimally adjust these factors could maximise the fibre-matrix stress-transfer efficiency and led to performance increases under various loading strain rates.
      Citation: Journal of Composites Science
      PubDate: 2021-05-13
      DOI: 10.3390/jcs5050130
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 131: Cohesive Zone Modeling of the
           Elastoplastic and Failure Behavior of Polymer Nanoclay Composites

    • Authors: Uraching Chowdhury, Xiang-Fa Wu
      First page: 131
      Abstract: Cohesive zone model (CZM) is commonly used to deal with the nonlinear zone ahead of crack tips in materials with elastoplastic deformation behavior. This model is capable of predicting the behavior of crack initiation and growth. In this paper, CZM-based finite element analysis (FEA) is performed to examine the effects of processing parameters (i.e., the clay nanoparticle volume fraction and aspect ratio) in the mechanical behaviors of a polymeric matrix reinforced with aligned clay nanoparticles. The polymeric matrix is treated as an ideal elastoplastic solid with isotropic hardening behavior, whereas the clay nanoparticles are simplified as stiff, linearly elastic platelets. Representative volume elements (RVEs) of the resulting polymer nanoclay composites (PNCs) are adopted for FEA with the clay nanoparticle distributions to follow both stack and stagger configurations, respectively. In the study, four volume fractions (Vf = 2.5%, 5%, 7.5% and 10%) and four aspect ratios (ρ = 5, 7.5, 10, and 20) of the clay nanoparticles in the PNCs are considered. Detailed computational results show that either increasing volume fraction or aspect ratio of the clay nanoparticles enhances the effective tensile strength and stiffness of the PNCs. The progressive debonding process of the clay nanoparticles in the polymeric resin was predicted, and the debonding was initiated in the linearly elastic loading range. The numerical results also show that PNCs with stagger nanoparticle configuration demonstrate slightly higher values of the engineering stress than those based on the stack nanoparticle configuration at both varying volume fractions and aspect ratios of the clay nanoparticles. In addition, CZM-based FEA predicts a slightly lower stress field around the clay particles in PNCs than that without integration of CZM. The present computational studies are applicable for processing PNCs with controllable mechanical properties, especially the control of the key processing parameters of PNCs, i.e., the volume fraction and aspect ratio of the clay nanoparticles.
      Citation: Journal of Composites Science
      PubDate: 2021-05-14
      DOI: 10.3390/jcs5050131
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 132: Thermal and Mechanical Properties of
           Green Insulation Composites Made from Cannabis and Bark Residues

    • Authors: Konstantinos Ninikas, Andromachi Mitani, Dimitrios Koutsianitis, George Ntalos, Hamid R. Taghiyari, Antonios N. Papadopoulos
      First page: 132
      Abstract: The objective of this paper was to investigate the technical feasibility of manufacturing low density insulation particleboards that were made from two renewable resources, namely hemp fibers (Cannabis sativa) and pine tree bark, which were bonded with a non-toxic methyl cellulose glue, as a binder. Four types of panels were made, which consisted of varying mixtures of tree bark and hemp fibers (tree bark to hemp fibers percentages of 90:10, 80:20, 70:30, and 60:40). An additional set of panels was made, consisting only of bark. The results showed that addition of hemp fibers to furnish improved mechanical properties of boards to reach an acceptable level. The thermal conductivity unfavorably increased as hemp content increased, though all values were still within the acceptable range. Based on cluster analysis, board type 70:30 (with 30% hemp content) produced the highest mechanical properties as well as the optimal thermal conductivity value. It is concluded that low density insulation boards can be successfully produced using these waste raw materials.
      Citation: Journal of Composites Science
      PubDate: 2021-05-17
      DOI: 10.3390/jcs5050132
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 133: Experimental Design of Solid Particle
           Wear Behavior of Ni-Based Composite Coatings

    • Authors: Pragyan Senapati, Harekrushna Sutar, Rabiranjan Murmu, Shubhra Bajpai
      First page: 133
      Abstract: The composition of nickel-based metal matrix NiCrBSi was varied with 5%, 10% and 15% of Al2O3 particles to obtain high wear resistant coatings by means of a high-velocity oxy fuel (HVOF) thermal spraying process. The coating was characterized by optical microscope, scanning electron microscope (SEM) and X-ray diffractometer (XRD). The physical properties of coatings such as porosity, thickness, surface roughness, surface hardness, fracture toughness, bond strength and density were measured and compared. The experimental design of Taguchi L27 orthogonal array was employed to study and compare the effect of parameters such as impingement angle, impact velocity and alumina per cent in the coating on erosion. The coating containing 15 wt.% of Al2O3 and erodent speed of 33 m/s striking at inclination angle of 30° proved to be the best arrangement in preventing volume loss to a minimum of 0.00015 cc due to low-impact energy, high bond strength and high surface hardness. Analysis of variance (ANOVA) supported the assertion that the impact angle (A) of erodent and composition (C) were the factors contributing most to the volumetric loss as indicated by their combined effect A × C leading to the highest combined factor of 7.34. The scanning electron microscopy (SEM) images of the eroded coatings reveal that the mechanisms of erosion were the fracturing of splats, development of craters, micro cutting and ploughing action.
      Citation: Journal of Composites Science
      PubDate: 2021-05-17
      DOI: 10.3390/jcs5050133
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 134: Preliminary Experimental and Numerical
           Study of Metal Element with Notches Reinforced by Composite Materials

    • Authors: Paweł J. Romanowicz, Bogdan Szybiński, Mateusz Wygoda
      First page: 134
      Abstract: The presented study is related to the application of the composite overlays used in order to decrease the effect of the stress concentrations around the cut-outs in structural metal elements. The proposed approach with the application of the digital image correlation extends the recently presented studies. Such structural elements with openings of various shapes have been accommodated for a wide range of industrial applications. These structures exhibit certain stress concentrations which decrease their durability and strength. To restore their strength, various reinforcing overlays can be used. In the present paper, the flat panel structure without and with the composite overlays made of HEXCEL TVR 380 M12/26%/R-glass/epoxy is under the experimental and the numerical study. Particular attention is paid to the investigation of the samples with the rectangular holes, which for smooth rounded corners offer a higher durability than the samples with the circular hole of the same size. The experimental results are obtained for the bare element and are reinforced with composite overlay samples. The experimental results are obtained with the use of the Digital Image Correlation method, while the numerical results are the product of the Finite Element Analysis. In the numerical analysis, the study of the shape, size and fiber orientation in applied overlays is done. The reduction of the stress concentration observed in opening notches has confirmed the effectiveness of the overlay application. In the investigated example, the application of the square composite overlay increased the structure strength even by 25%.
      Citation: Journal of Composites Science
      PubDate: 2021-05-18
      DOI: 10.3390/jcs5050134
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 135: Multiscale Toughening of Composites
           with Carbon Nanotubes—Continuous Multiscale Reinforcement New Concept

    • Authors: Monssef Drissi-Habti, Yassine El Assami, Venkadesh Raman
      First page: 135
      Abstract: Strengthening composite structures for advanced industries such as offshore wind generation is a real issue. Due to the huge dimensions expected for next generation wind-blades, composites based on glass fibers can no longer be used due to the lack of stiffness, whereas composites based on carbon fibers are expensive. Therefore, switching to alternative structural solutions is highly needed. This might be achieved by appropriate use of carbon nanotubes (CNTs) either as fillers of epoxy matrices, especially in inter-plies, or as fillers of epoxy glues used in structural bonding joints. As an example, trailing edges of offshore wind-blades are addressed in the current article, where monolithic bonding holds together the two structural halves and where the risk of sudden and brittle separation of edges while wind-turbines are in service is quite high. This can lead to tedious and very expensive maintenance, especially when keeping in mind the huge dimensions of new generation wind turbine blades that exceed lengths of 100 m. Bond joints and composites inter-plies of the final CNT-reinforced structures will exhibit stiffness and toughness high enough to face the severe offshore environment. In this article, multiscale Finite Element (FE) modeling is carried out to evaluate mechanical properties following the addition of CNTs. To achieve an optimal reinforcement, the effect of inclination of CNTs vs. mechanical loading axis is studied. Two innovations are suggested through this numerical study: The first consists of using homogenization in order to evaluate the effects of CNT reinforcement macroscopically. The second innovation lies in this forward-looking idea to envisage how we can benefit from CNTs in continuous fiber composites, as part of a deep theoretical rethinking of the reinforcement mechanisms operating at different scales and their triggering kinetics. The presented work is purely numerical and should be viewed as a “scenario” of structural composite materials of the future, which can be used both in the offshore industry and in other advanced industries. More broadly and through what is proposed, we humbly wish to stimulate scientific discussions about how we can better improve the performances of structural composite materials.
      Citation: Journal of Composites Science
      PubDate: 2021-05-18
      DOI: 10.3390/jcs5050135
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 136: Maximizing the Performance of 3D
           Printed Fiber-Reinforced Composites

    • Authors: S M Fijul Kabir, Kavita Mathur, Abdel-Fattah M. Seyam
      First page: 136
      Abstract: Fiber-reinforced 3D printing technology offers significant improvement in the mechanical properties of the resulting composites relative to 3D printed (3DP) polymer-based composites. However, 3DP fiber-reinforced composite structures suffer from low fiber content compared to the traditional composite, such as 3D orthogonal woven preforms solidified with vacuum assisted resin transfer molding (VARTM) that impedes their high-performance applications such as in aerospace, automobile, marine and building industries. The present research included fabrication of 3DP fiberglass-reinforced nylon composites, with maximum possible fiber content dictated by the current 3D printing technology at varying fiber orientations (such as 0/0, 0/90, ±45 and 0/45/90/−45) and characterizing their microstructural and performance properties, such as tensile and impact resistance (Drop-weight, Izod and Charpy). Results indicated that fiber orientation with maximum fiber content have tremendous effect on the improvement of the performance of the 3DP composites, even though they inherently contain structural defects in terms of voids resulting in premature failure of the composites. Benchmarking the results with VARTM 3D orthogonal woven (3DOW) composites revealed that 3DP composites had slightly lower tensile strength due to poor matrix infusion and voids between adjacent fiber layers/raster, and delamination due to lack of through-thickness reinforcement, but excellent impact strength (224% more strong) due to favorable effect of structural voids and having a laminated structure developed in layer-by-layer fashion.
      Citation: Journal of Composites Science
      PubDate: 2021-05-18
      DOI: 10.3390/jcs5050136
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 137: Temperature Study during the Edge
           Trimming of Carbon Fiber-Reinforced Plastic [0]8/Ti6Al4V Stack Material

    • Authors: Arquimedes Castillo-Morales, Xavier Rimpault, Jean-François Chatelain, Gilbert Lebrun
      First page: 137
      Abstract: Carbon Fiber-Reinforced Plastic (CFRP) and Titanium alloy (Ti6Al4V) stacks are used extensively in the modern aerospace industry thanks to their outstanding mechanical properties and resistance to thermal load applications. Machining the CFRP/Ti6Al4V stack is a challenge and is complicated by the differences in each constituent materials’ machinability. The difficulty arises from the matrix degradation of the CFRP material caused by the heat generated during the machining process, which is a consequence of the low thermal conductivity of Ti6Al4V material. In most cases, CFRP and Ti6Al4V materials are stacked and secured together using rivets or bolts. This results in extra weight, while the drilling process required for such an assembly may damage the CFRP material. To overcome these issues, some applications employ an assembly that is free of bolts or rivets, and which uses adhesives or an adapted curing process to bond both materials together. The present research analyzes a thermal distribution and its effect on quality during the edge trimming process of a CFRP/Ti6Al4V stack assembly. Different types of tools and cutting parameters are compared using thermocouples embedded within the material and others on the tool cutting edge. In contrast to previous studies, the feed rate was the most significant factor affecting the cutting temperature and quality of the workpiece, while the cutting speed had no significant impact. The temperature in the workpiece increases as the feed per tooth decreases.
      Citation: Journal of Composites Science
      PubDate: 2021-05-19
      DOI: 10.3390/jcs5050137
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 138: Recent Advances in Multi-Scale
           Experimental Analysis to Assess the Role of Compatibilizers in Cellulosic
           Filler-Reinforced Plastic Composites

    • Authors: Yoshikuni Teramoto
      First page: 138
      Abstract: Adding acid-modified resin compatibilizers is essential for plastic composites reinforced with carbon-neutral cellulosic filler. Researchers have measured the efficacy of adding a compatibilizer in the context of mechanics. However, it is necessary to microscopically clarify how the compatibilizer actually works for quality control and further expansion of applications. In this review, the author first describes the situation of cellulosic composites and presents issues regarding how one assesses the role of the compatibilizer. The author then reviews recent multi-scale experimental approaches to the detection of covalent bonds between the cellulosic filler and compatibilizer, estimation of nanoscale interphases, and the micron-scale dispersibility of the fillers. With accumulation of such experimental facts, appropriate parameter settings can be expected for the structural analysis such as the finite-element method, as well as the potential to provide appropriate explanatory variables for material/process informatics.
      Citation: Journal of Composites Science
      PubDate: 2021-05-20
      DOI: 10.3390/jcs5050138
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 139: Demagnetization Effect on the
           Magnetoelectric Response of Composite Multiferroic Cylinders

    • Authors: Somer Nacy, George Youssef
      First page: 139
      Abstract: Strain-mediated multiferroic composite structures are gaining scientific and technological attention because of the promise of low power consumption and greater flexibility in material and geometry choices. In this study, the direct magnetoelectric coupling coefficient (DME) of composite multiferroic cylinders, consisting of two mechanically bonded concentric cylinders, was analytically modeled under the influence of a radially emanating magnetic field. The analysis framework emphasized the effect of demagnetization on the overall performance. The demagnetization effect was thoroughly considered as a function of the imposed mechanical boundary conditions, the geometrical dimensions of the composite cylinder, and the introduction of a thin elastic layer at the interface between the inner piezomagnetic and outer piezoelectric cylinders. The results indicate that the demagnetization effect adversely impacted the DME coefficient. In a trial to compensate for the reduction in peak DME coefficient due to demagnetization, a non-dimensional geometrical analysis was carried out to identify the geometrical attributes corresponding to the maximum DME. It was observed that the peak DME coefficient was nearly unaffected by varying the inner radius of the composite cylinder, while it approached its maximum value when the thickness of the piezoelectric cylinder was almost 60% of the total thickness of the composite cylinder. The latter conclusion was true for all of the considered boundary conditions.
      Citation: Journal of Composites Science
      PubDate: 2021-05-20
      DOI: 10.3390/jcs5050139
      Issue No: Vol. 5, No. 5 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 92: Multi-Objective Optimization of
           Functionally Graded Beams Using a Genetic Algorithm with Non-Dominated
           Sorting

    • Authors: Chih-Ping Wu, Kuan-Wei Li
      First page: 92
      Abstract: A mixed layer-wise (LW) higher-order shear deformation theory (HSDT) is developed for the thermal buckling analysis of simply-supported, functionally graded (FG) beams subjected to a uniform temperature change. The material properties of the FG beam are assumed to be dependent on the thickness and temperature variables, and the effective material properties are estimated using either the rule of mixtures or the Mori–Tanaka scheme. The results shown in the numerical examples indicate the mixed LW HSDT solutions for critical temperature change parameters are in excellent agreement with the accurate solutions available in the literature. A multi-objective optimization of FG beams is presented to maximize the critical temperature change parameters and to minimize their total mass using a non-dominated sorting-based genetic algorithm. Some specific forms for the volume fractions of the constituents of the FG beam are assumed in advance, such as the one- and three-parameter power-law functions. The former is used in the thermal buckling analysis of the FG beams for comparison purposes, and the latter is used in their optimal design.
      Citation: Journal of Composites Science
      PubDate: 2021-03-30
      DOI: 10.3390/jcs5040092
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 93: Development of a Shape Replicating
           Draping Unit for Continuous Layup of Unidirectional Non-Crimp Fabrics on
           Complex Surface Geometries

    • Authors: Berend Denkena, Carsten Schmidt, Simon Werner, Dietmar Schwittay
      First page: 93
      Abstract: The manufacturing of large-scale structural components is still dominated by manual labor in many sectors of the modern composite industry. Efforts are being made to establish an automated layup technology for complex structural elements. Processing dry non-crimp fiber fabrics (NCF) offers great cost opportunities and high deposition rates, compared to prepreg-based technologies like automated fiber placement (AFP). Here, the fabric architecture is considered during the draping of the plane textile on curved surfaces. In this paper, the development of a draping unit for balancing fabric tension and consolidating continuously across the layup width is presented. We introduce a geometrical process model to achieve a fabric-friendly draping of the used unidirectional NCF. The shape of the resulting draping front depends on the surface geometry, the shearing of the previously laid-up textile, and the positioning of the material feed. To consolidate the fabric at the altering draping front in an automated layup process, the shape of the continuous consolidation element can be controlled by the elongation of serial soft actuators, manipulated by parallel robot kinematics. The shape replication ability of the draping unit is promising for the implementation of a continuous, fabric-friendly draping process for complex surface geometries.
      Citation: Journal of Composites Science
      PubDate: 2021-04-01
      DOI: 10.3390/jcs5040093
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 94: Flexural Characteristics of
           Functionally Graded Fiber-Reinforced Cementitious Composite with Polyvinyl
           Alcohol Fiber

    • Authors: Toshiyuki Kanakubo, Takumi Koba, Kohei Yamada
      First page: 94
      Abstract: The objective of this study is to investigate the flexural characteristics of functionally graded fiber-reinforced cementitious composite (FG-FRCC) concerning the fiber volume fraction (Vf) varying in layers and the layered effect in bending specimens. The FG-FRCC specimens, in which Vf increases from 0% in the compression zone to 2% in the tensile zone, are three-layered specimens using polyvinyl alcohol (PVA) FRCC that are fabricated and tested by a four-point bending test. The maximum load of the FG-FRCC specimens exhibits almost twice that of homogeneous specimens, even when the average of the fiber volume fraction in the whole specimen is 1%. The result of the section analysis, in which the stress–strain models based on the bridging law (tensile stress–crack width relationship owned by the fibers) consider the fiber orientation effect, shows a good adaptability with the experiment result.
      Citation: Journal of Composites Science
      PubDate: 2021-04-01
      DOI: 10.3390/jcs5040094
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 95: Assessment of Replacement of Metal
           Parts by BFRP Composites into a Highly Efficient Electrical Prototype

    • Authors: Rosa Marat-Mendes, Diogo Ribeira, Luís Reis
      First page: 95
      Abstract: This work intends to evaluate the use of epoxy composite materials reinforced with basalt fibers as replacement to metallic mechanical parts of a highly efficient electrical prototype. The analysis of the behavior of the original metallic bracket was made and an optimization process was carried out in order to achieve the most suitable geometry and stacking sequence if produced in composite material. Finite element analysis using Siemens NX12 and experimental tests to the produced composite part were performed in order to access it. It was verified that the total weight of the composite part shows a 45% reduction. The composite part shows a higher deformation than the metallic one due to basalt fiber’s higher flexibility. However, the advantages added by the new component largely compensate for the disadvantages that may have been added without compromising its performance. Obtained results show that the use of basalt fiber reinforced composites as the material of mechanical parts of a highly efficient electrical prototype that is a good alternative.
      Citation: Journal of Composites Science
      PubDate: 2021-04-01
      DOI: 10.3390/jcs5040095
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 96: A Review on the Usage of Continuous
           Carbon Fibers for Piezoresistive Self Strain Sensing Fiber Reinforced
           Plastics

    • Authors: Patrick Scholle, Michael Sinapius
      First page: 96
      Abstract: This literature review examines the application of carbon fibers and their reinforced plastics for Self-Strain-Sensing structures and gives an up-to-date overview of the existing research. First, relevant basic experimental approaches that can be found in the literature are presented and discussed. Next, we propose to cluster the available articles into 5 categories based on specimen size and ranging from experiments on bare carbon fiber via impregnated fiber rovings to carbon fiber laminates. Each category is analyzed individually and the potential differences between them are discussed based on experimental evidence found in the past. The overview shows, that the choice of carbon fiber and the specific experimental setup both significantly influence the piezoresistive properties measured in Self-Strain-Sensing carbon fiber reinforced plastics. Conclusively, based on the conclusions drawn from the literature review, we propose a small number of measurements that have proven to be important for the analysis of Self-Strain-Sensing carbon fiber structures.
      Citation: Journal of Composites Science
      PubDate: 2021-04-02
      DOI: 10.3390/jcs5040096
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 97: DMSO Deintercalation in
           Kaolinite–DMSO Intercalate: Influence of Solution Polarity on Removal

    • Authors: Berenger ZOGO MFEGUE, Jean Aimé MBEY, Sandotin Lassina COULIBALY, Vincent Laurent ONANA, Paul-Désiré NDJIGUI
      First page: 97
      Abstract: This study focused on the deintercalation of dimethyl sulfoxide (DMSO) from a kaolinite–DMSO complex in various solvents. The use of kaolinite as filler in polymer–clay composite generally faced the difficulty of kaolinite dispersion due to its high cohesion. For improved dispersion of kaolinite within a given matrix, previous intercalation of small polar molecules is usually done prior to its displacement during composite-making. The influence of the solvent polarity on the deintercalation in analyzed here to understand its role during the deintercalation process. The intercalation of the DMSO was done by solution-mixing and its displacement was done in distilled water, ethyl acetate, and acetone. The products of deintercalation were analyzed using Fourier transform infra-red (FTIR), powder X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The weakening of the kaolinite cohesion after DMSO intercalation is demonstrated through the broadening of the diffraction peak associated with the kaolinite on XRD patterns. From FTIR spectra, the weakening is associated with the displacement to low wavenumbers of the Si–O or Al–O vibration bands within the kaolinite–DMSO complex. The kaolinite dehydroxylation temperatures from DSC show that the rate of DMSO displacement affects the ordering of the recovered kaolinite. The crystallite size of the kaolinite is reduced from the raw to the recovered kaolinite after DMSO displacement, indicating an exfoliation of the kaolinite. From these results, it is found that the removal of the DMSO from the kaolinite–DMSO complex is influenced by solvent polarity. The higher the polarity, the greater the removal of the DMSO from the complex. Solvent polarity affects the rate of DMSO displacement, which influences the ordering of the recovered kaolinite. It is suggested that solvent polarity can be used to control the removal rate of DMSO, which may be key to the dispersion of the kaolinite platelets.
      Citation: Journal of Composites Science
      PubDate: 2021-04-02
      DOI: 10.3390/jcs5040097
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 98: In Vivo Effects of Two In-Office Vital
           Tooth Bleaching Systems on Enamel Permeability

    • Authors: Angelica Bertacci, Gianfranco Ulian, Daniele Moro, Stefano Chersoni, Giovanni Valdrè
      First page: 98
      Abstract: Tooth bleaching is a common treatment for the amelioration of the aesthetic of discoloured teeth. In this context, there are two common approaches that employ concentrated solutions (30–40 wt.%) of either hydrogen peroxide or carbamide peroxide as bleaching agents. However, there is an ongoing debate on the possible adverse effects of these different treatments on tooth health, such as variation of the enamel structure, surface morphology, and chemistry, which also affect tooth sensitivity. In the present work, a study on the effect of the two bleaching agents, a 35 wt.% solution of hydrogen peroxide and a 30 wt.% solution of carbamide peroxide, on the permeability and surface morphology of enamel is reported. The investigation was carried out on replicas of incisors obtained after different treatment times and for several patients, employing scanning electron microscopy to study the morphological features of the treated teeth. The significance of the analytical study was corroborated by a statistical analysis of the results. The collected data suggest that hydrogen peroxide treatment increases the enamel permeability, and this could be related with tooth sensitivity, whereas the carbamide peroxide solution increases the formation of precipitates on the tooth enamel.
      Citation: Journal of Composites Science
      PubDate: 2021-04-04
      DOI: 10.3390/jcs5040098
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 99: SEM Evaluation of Endosequence BC
           Sealer Hiflow in Different Environmental Conditions

    • Authors: Orlando Donfrancesco, Andrea Del Giudice, Alessio Zanza, Michela Relucenti, Stefano Petracchiola, Gianluca Gambarini, Luca Testarelli, Marco Seracchiani
      First page: 99
      Abstract: The aim of the present study is to evaluate the setting and sealant ability of two different bioceramic sealers in two different environmental conditions: humid and wet environment. Ex vivo root canal treatment was performed on 24 freshly extracted teeth. Irrigation was performed with Niclor NaOCl 5% and EDTA 17%, then obturated with a bioceramic sealer in the two different environmental conditions listed above. Furthermore, scanning electron microscope (SEM) investigation was performed to verify the presence of gaps and the setting ability of the two sealers in two different environmental conditions was evaluated. While presence of gaps was found mainly in the wet specimens, on the other hand, regarding the setting ability, there is no statistically significant difference between the two different samples. Therefore, even if humid conditions represent the gold standard in terms of lower gaps dimension, since there is no methodology standardizing the drying procedure of the root canal, it is compulsory to investigate the sealing ability of the bioceramic sealers, even in wet conditions. Thanks to the findings shown in the present study, it is demonstrated that even in wet conditions the ability of the sealer to set does not change and such clinical situation could affect the bioceramic sealer protocol.
      Citation: Journal of Composites Science
      PubDate: 2021-04-04
      DOI: 10.3390/jcs5040099
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 100: Improvement of Performance Profile of
           Acrylic Based Polyester Bio-Composites by Bast/Basalt Fibers Hybridization
           for Automotive Applications

    • Authors: Anjum Saleem, Luisa Medina, Mikael Skrifvars
      First page: 100
      Abstract: New technologies in the automotive industry require lightweight, environment-friendly, and mechanically strong materials. Bast fibers such as kenaf, flax, and hemp reinforced polymers are frequently used composites in semi-structural applications in industry. However, the low mechanical properties of bast fibers limit the applications of these composites in structural applications. The work presented here aims to enhance the mechanical property profile of bast fiber reinforced acrylic-based polyester resin composites by hybridization with basalt fibers. The hybridization was studied in three resin forms, solution, dispersion, and a mixture of solution and dispersion resin forms. The composites were prepared by established processing methods such as carding, resin impregnation, and compression molding. The composites were characterized for their mechanical (tensile, flexural, and Charpy impact strength), thermal, and morphological properties. The mechanical performance of hybrid bast/basalt fiber composites was significantly improved compared to their respective bast fiber composites. For hybrid composites, the specific flexural modulus and strength were on an average about 21 and 19% higher, specific tensile modulus and strength about 31 and 16% higher, respectively, and the specific impact energy was 13% higher than bast fiber reinforced composites. The statistical significance of the results was analyzed using one-way analysis of variance.
      Citation: Journal of Composites Science
      PubDate: 2021-04-04
      DOI: 10.3390/jcs5040100
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 101: Metal-Organic Framework-Based
           Stimuli-Responsive Polymers

    • Authors: Menglian Wei, Yu Wan, Xueji Zhang
      First page: 101
      Abstract: Metal-organic framework (MOF) based stimuli-responsive polymers (coordination polymers) exhibit reversible phase-transition behavior and demonstrate attractive properties that are capable of altering physical and/or chemical properties upon exposure to external stimuli, including pH, temperature, ions, etc., in a dynamic fashion. Thus, their conformational change can be imitated by the adsorption/desorption of target analytes (guest molecules), temperature or pressure changes, and electromagnetic field manipulation. MOF-based stimuli responsive polymers have received great attention due to their advanced optical properties and variety of applications. Herein, we summarized some recent progress on MOF-based stimuli-responsive polymers (SRPs) classified by physical and chemical responsiveness, including temperature, pressure, electricity, pH, metal ions, gases, alcohol and multi-targets.
      Citation: Journal of Composites Science
      PubDate: 2021-04-07
      DOI: 10.3390/jcs5040101
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 102: Isosteric Enthalpy Behavior of CO2
           Adsorption on Micro-Mesoporous Materials: Carbon Microfibers (CMFs),
           SBA-15, and Amine-Functionalized SBA-15

    • Authors: Reyna Ojeda-López, Armando Domínguez-Ortiz, Carlos Felipe, A. Cervantes-Uribe, Isaac J. Pérez-Hermosillo, J. Marcos Esparza-Schulz
      First page: 102
      Abstract: The isosteric enthalpy of adsorption (Δadsh˙) of CO2 in three different micro and mesoporous materials was evaluated in this work. These materials were a microporous material with functional groups of nitrogen and oxygen (CMFs, carbon microfibers), a mesoporous material with silanol groups (SBA-15, Santa Barbara Amorphous), and a mesoporous material with amine groups (SBA-15_APTES, SBA-15 amine-functionalized with (3-Aminopropyl)-triethoxysilane). The temperature interval explored was between 263 K and 303 K, with a separation of 5 K between each one, so a total of nine CO2 isotherms were obtained. Using the nine isotherms and the Clausius–Clapeyron equation, the reference value for Δadsh˙ was found. The reference value was compared with those Δadsh˙ obtained, considering some arrangement of three or five CO2 isotherms. Finally, it was found that at 298 K and 1 bar, the total amount of CO2 adsorbed is 2.32, 0.53, and 1.37 mmol g−1 for CMF, SBA-15, and SBA-15_APTES, respectively. However, at a coverage of 0.38 mmol g−1, Δadsh˙ is worth 38, 30, and 29 KJ mol−1 for SBA-15_APTES, CMFs, and SBA-15, respectively. So, physisorption predominates in the case of CMF and SBA-15 materials, and the Δadsh˙ values significantly coincide regardless of whether the isotherms arrangement used was three or five. Meanwhile, in SBA-15_APTES, chemisorption predominates as a consequence of the arrangements used to obtain Δadsh˙. This happens in such a way that the use of low temperatures (263–283 K) tends to produce higher Δadsh˙ values, while the use of high temperatures (283–303 K) decreases the Δadsh˙ values.
      Citation: Journal of Composites Science
      PubDate: 2021-04-08
      DOI: 10.3390/jcs5040102
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 103: Investigating the Hall-Petch Constants
           for As-Cast and Aged AZ61/CNTs Metal Matrix Composites and Their Role on
           Superposition Law Exponent

    • Authors: Aqeel Abbas, Song-Jeng Huang
      First page: 103
      Abstract: AZ61/carbon nanotubes (CNTs) (0, 0.1, 0.5, and 1 wt.%) composites were successfully fabricated by using the stir-casting method. Hall–Petch relationship and superposition of different strengthening mechanisms were analyzed for aged and as-cast AZ61/CNTs composites. Aged composites showed higher frictional stress (108.81 MPa) than that of as-cast (31.56 Mpa) composites when the grain size was fitted directly against the experimentally measured yield strength. In contrast, considering the superposition of all contributing strengthening mechanisms, the Hall–Petch constants contributed by only grain-size strengthening were found (σ0 = 100.06 Mpa and Kf = 0.3048 Mpa m1/2) for as-cast and (σ0 = 87.154 Mpa and Kf = 0.3407 Mpa m1/2) for aged composites when superposition law exponent is unity. The dislocation density for the as-cast composites was maximum (8.3239 × 1013 m−2) in the case of the AZ61/0.5 wt.%CNT composite, and for aged composites, it increased with the increase in CNTs concentration and reached the maximum value (1.0518 × 1014 m−2) in the case of the AZ61/1 wt.%CNT composite.
      Citation: Journal of Composites Science
      PubDate: 2021-04-09
      DOI: 10.3390/jcs5040103
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 104: Development of a Reactive Polyurethane
           Foam System for the Direct Sandwich Composite Molding (D-SCM) Process

    • Authors: Felix Behnisch, Viktoria Lichtner, Frank Henning, Philipp Rosenberg
      First page: 104
      Abstract: Sandwich structures utilize the geometric stiffening effect by increasing the area moment of inertia. This reduces carbon fiber (CF) material within CF-reinforced plastic (CFRP) components, and thus, the CO2 footprint. A suitable material combination for lightweight design is the use of continuous fiber-reinforced face sheets with a light foam core. CFRP sandwich structures with foam core are manufactured by combining a prefabricated foam core with fiber-reinforced cover layers in a two-step press process. Besides the reduction of the used CFRP material, more efficient manufacturing processes are needed. The aim of this paper is to develop a novel polyurethane foam system to enable the direct sandwich composite molding (D‑SCM) process for the production of CFRP sandwich structures by utilizing the resulting foaming pressure during the reactive polyurethane (PUR) foam system expansion for the impregnation of the CF reinforced face sheets. The developed formulation enables D-SCM structures with 150–250 kg/m3 foam density and 44–47.5% fiber volume content, based on a preliminary evaluation.
      Citation: Journal of Composites Science
      PubDate: 2021-04-11
      DOI: 10.3390/jcs5040104
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 105: Effect of Hydrogels Containing
           Nanosilica on the Properties of Cement Pastes

    • Authors: Babak Vafaei, Khashayar Farzanian, Ali Ghahremaninezhad
      First page: 105
      Abstract: The effect of hydrogels containing nanosilica (NSi) on the autogenous shrinkage, mechanical strength, and electrical resistivity of cement pastes was studied. The interaction between the hydrogels and the surrounding cementitious matrix was examined using thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The addition of hydrogels decreased autogenous shrinkage in the cement pastes and this reduction showed a dependence on the concentration of NSi in the hydrogels. Compressive strength and electrical resistivity were reduced in the cement pastes with hydrogels and this reduction was decreased with increased concentration of NSi in the hydrogel. A change in the phase composition of the cement paste in the region close to the hydrogel was noted, compared to the region away from the hydrogel. In a lime solution with increased pH and temperature, Ca(OH)2 and CaCO3 were found to form within the hydrogels; evidence of calcium-silicate-hydrate (C-S-H) formation in the hydrogels with NSi was obtained, indicating the possible pozzolanic potential of the hydrogels with NSi.
      Citation: Journal of Composites Science
      PubDate: 2021-04-12
      DOI: 10.3390/jcs5040105
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 106: Color Stability of CAD/CAM Interim
           Material for Long-Term Fixed Dental Prostheses vs. Conventional Materials
           after Immersion in Different Staining Solutions

    • Authors: Lissethe Peñate, Montse Mercade, María Arregui, Miguel Roig, Juan Basilio, Rosario Cedeño
      First page: 106
      Abstract: The color stability of interim computer-aided design and computer-assisted manufacturing (CAD/CAM) materials has not been exhaustively investigated. The aim of this study was to compare the translucency (TP) and contrast ratio (CR) of CAD/CAM blocks and conventional interim materials, as well as the effects of varnish application and tooth-brushing on color stability after immersion in different staining solutions. Four hundred and eighty specimens were fabricated with four different interim materials (n = 120) and were divided into three experimental, and one control group (n = 30). The color measurements were taken at the initial time (T0), 24 h (T1), 7 days (T2), and 30 days (T3) after immersion in different solutions. CIEDE2000 (ΔE00) values were analyzed with ANOVA and Fischer’s LSD test with a 95% confidence interval. The relationship between TP and CR was analyzed with a Pearson correlation. All interim materials showed a significant difference (p < 0.05) in color change after 30 days. Results showed that polyethyl methacrylate resins (PEMA) had the highest stability over time. The TP and CR were statistically significant (p < 0.05). It was observed that brushing improved the color stability but the ΔE00 were the highest when the varnish alone or varnish and brushing were used, except in the bis-acryl group, in which varnish and brushing decreased the color stainability.
      Citation: Journal of Composites Science
      PubDate: 2021-04-13
      DOI: 10.3390/jcs5040106
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 107: Assessment of Analytical Orientation
           Prediction Models for Suspensions Containing Fibers and Spheres

    • Authors: Bastien Dietemann, Fatih Bosna, Harald Kruggel-Emden, Torsten Kraft, Claas Bierwisch
      First page: 107
      Abstract: Analytical orientation models like the Folgar Tucker (FT) model are widely applied to predict the orientation of suspended non-spherical particles. The accuracy of these models depends on empirical model parameters. In this work, we assess how well analytical orientation models can predict the orientation of suspensions not only consisting of fibers but also of an additional second particle type in the shape of disks, which are varied in size and filling fraction. We mainly focus on the FT model, and we also compare its accuracy to more complex models like Reduced-Strain Closure model (RSC), Moldflow Rotational Diffusion model (MRD), and Anisotropic Rotary Diffusion model (ARD). In our work, we address the following questions. First, can the FT model predict the orientation of suspensions despite the additional particle phase affecting the rotation of the fibers' Second, is it possible to formulate an expression for the sole Folgar Tucker model parameter that is based on the suspension composition' Third, is there an advantage to choose more complex orientation prediction models that require the adjustment of additional model parameters'
      Citation: Journal of Composites Science
      PubDate: 2021-04-13
      DOI: 10.3390/jcs5040107
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 108: Fabrication of Porous Carbon Films and
           Their Impact on Carbon/Polypropylene Interfacial Bonding

    • Authors: Yucheng Peng, Ruslan Burtovyy, Rajendra Bordia, Igor Luzinov
      First page: 108
      Abstract: Porous carbon films were generated by thermal treatment of polymer films made from poly(acrylonitrile-co-methyl acrylate)/polyethylene terephthalate (PAN/PET) blend. The precursor films were fabricated by a dip-coating process using PAN/PET solutions in hexafluoro-2-propanol (HFIP). A two-step process, including stabilization and carbonization, was employed to produce the carbon films. PET functioned as a pore former. Specifically, porous carbon films with thicknesses from 0.38–1.83 μm and pore diameters between 0.1–10 μm were obtained. The higher concentrations of PET in the PAN/PET mixture and the higher withdrawal speed during dip-coating caused the formation of larger pores. The thickness of the carbon films can be regulated using the withdrawal speed used in the dip-coating deposition. We determined that the deposition of the porous carbon film on graphite substrate significantly increases the value of the interfacial shear strength between graphite plates and thermoplastic PP. This study has shown the feasibility of fabrication of 3D porous carbon structure on the surface of carbon materials for increasing the interfacial strength. We expect that this approach can be employed for the fabrication of high-performance carbon fiber-thermoplastic composites.
      Citation: Journal of Composites Science
      PubDate: 2021-04-14
      DOI: 10.3390/jcs5040108
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 109: Recent Advances in Geopolymer
           Technology. A Potential Eco-Friendly Solution in the Construction
           Materials Industry: A Review

    • Authors: Matteo Sambucci, Abbas Sibai, Marco Valente
      First page: 109
      Abstract: In the last ten years, the Portland cement industry has received wide criticism due to its related high embodied energy and carbon dioxide footprint. Recently, numerous “clean” strategies and solutions were developed. Among these, geopolymer technology is gaining growing interest as a functional way to design more eco-friendly construction materials and for waste management issues suffered by various industries. Previous research has highlighted the attractive engineering properties of geopolymeric materials, especially in terms of mechanical properties and durability, resulting in even higher performance than ordinary concrete. This review provides a comprehensive analysis of current state-of-the-art and implementations on geopolymer concrete materials, investigating how the key process factors (such as raw materials, synthesis regime, alkali concentration, water dosage, and reinforcement fillers) affect the rheological, microstructural, durability, and mechanical properties. Finally, the paper elucidates some noteworthy aspects for future research development: innovative geopolymer-based formulations (including alkali-activated blends for additive manufacturing and thermo-acoustic insulating cellular compounds), concrete applications successfully scaled in the civil-architectural fields, and the perspective directions of geopolymer technology in terms of commercialization and large-scale diffusion.
      Citation: Journal of Composites Science
      PubDate: 2021-04-17
      DOI: 10.3390/jcs5040109
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 110: Composite Material of PDMS with
           Interchangeable Transmittance: Study of Optical, Mechanical Properties and
           Wettability

    • Authors: Flaminio Sales, Andrews Souza, Ronaldo Ariati, Verônica Noronha, Elder Giovanetti, Rui Lima, João Ribeiro
      First page: 110
      Abstract: Polydimethylsiloxane (PDMS) is a polymer that has attracted the attention of researchers due to its unique properties such as transparency, biocompatibility, high flexibility, and physical and chemical stability. In addition, PDMS modification and combination with other materials can expand its range of applications. For instance, the ability to perform superhydrophobic coating allows for the manufacture of lenses. However, many of these processes are complex and expensive. One of the most promising modifications, which consists of the development of an interchangeable coating, capable of changing its optical characteristics according to some stimuli, has been underexplored. Thus, we report an experimental study of the mechanical and optical properties and wettability of pure PDMS and of two PDMS composites with the addition of 1% paraffin or beeswax using a gravity casting process. The composites’ tensile strength and hardness were lower when compared with pure PDMS. However, the contact angle was increased, reaching the highest values when using the paraffin additive. Additionally, these composites have shown interesting results for the spectrophotometry tests, i.e., the material changed its optical characteristics when heated, going from opaque at room temperature to transparent, with transmittance around 75%, at 70 °C. As a result, these materials have great potential for use in smart devices, such as sensors, due to its ability to change its transparency at high temperatures.
      Citation: Journal of Composites Science
      PubDate: 2021-04-17
      DOI: 10.3390/jcs5040110
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 111: Optimization of Process Conditions for
           Continuous Growth of CNTs on the Surface of Carbon Fibers

    • Authors: Chengjuan Wang, Yanxiang Wang, Shunsheng Su
      First page: 111
      Abstract: Grafting carbon nanotubes (CNTs) is one of the most commonly used methods for modifying carbon fiber surface, during which complex device is usually needed and the growth of CNTs is difficult to control. Herein, we provide an implementable and continuous chemical vapor deposition (CVD) process, by which the novel multiscale reinforcement of carbon nanotube (CNT)-grafted carbon fiber is prepared. After exploring the effects of the moving speed and growth atmosphere on the morphology and mechanical properties of carbon nanotubes/carbon fiber (CNTs/CF) reinforcement, the optimal CVD process conditions are determined. The results show that low moving speeds of carbon fibers passing through the reactor can prolong the growth time of CNTs, increasing the thickness and density of the CNTs layer. When the moving speed is 3 cm/min or 4 cm/min, the surface graphitization degree and tensile strength of CNTs/CF almost simultaneously reach the highest value. It is also found that H2 in the growth atmosphere can inhibit the cracking of C2H2 and has a certain effect on prolonging the life of the catalyst. Meanwhile, the graphitization degree is promoted gradually with the increase in H2 flow rate from 0 to 0.9 L/min, which is beneficial to CNTs/CF tensile properties.
      Citation: Journal of Composites Science
      PubDate: 2021-04-17
      DOI: 10.3390/jcs5040111
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 112: Effect of Defects Part II: Multiscale
           Effect of Microvoids, Orientation of Rivet Holes on the Damage
           Propagation, and Ultimate Failure Strength of Composites

    • Authors: Vahid Tavaf, Mohammadsadegh Saadatzi, Sourav Banerjee
      First page: 112
      Abstract: Material properties at the vicinity of the cut-outs in composites are not entirely defect-free. The nteraction of multiple cutouts like rivet holes, the repercussion of their configuration on crack propagation, and ultimate strength were predicted using Peridynamic method and the results are reported in this article. The effect of microscale defects at the vicinity of the cutouts on macroscale damage propagation were shown to have quantifiable manifestation. This study focused on two to four holes in unidirectional composite plates with 0°, 45°, and 90° fiber directions, while the vicinity of a hole was considered degraded. Numerical results were validated using quantitative ultrasonic image correlation (QUIC) and the tensile test. Both the experimental and numerical results confirmed that the strength of the horizontal configuration is higher than the vertical in the plates with two holes. Furthermore, the square configuration was found to be stronger than the diamond configuration with four holes. When the effect of microscale defects was considered, the prediction of ultimate strength was better compared to the experimental results. The predictive model could be reliably used for progressive damage analysis.
      Citation: Journal of Composites Science
      PubDate: 2021-04-17
      DOI: 10.3390/jcs5040112
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 113: Development of Ultra-Lightweight and
           High Strength Engineered Cementitious Composites

    • Authors: Zhitao Chen, Junxia Li, En-Hua Yang
      First page: 113
      Abstract: In this study, ultra-lightweight and high strength Engineered Cementitious Composites (ULHS-ECCs) are developed via lightweight filler incorporation and matrix composition tailoring. The mechanical, physical, and micromechanical properties of the resulting ULHS-ECCs are investigated and discussed. ULHS-ECCs with a density below 1300 kg/m3, a compressive strength beyond 60 MPa, a tensile strain capacity above 1%, and a thermal conductivity below 0.5 w/mK are developed. The inclusion of lightweight fillers and the variation in proportioning of the ternary binder can lead to a change in micromechanical properties, including the matrix fracture toughness and the fiber/matrix interface properties. As a result, the tensile strain-hardening performance of the ULHS-ECCs can be altered.
      Citation: Journal of Composites Science
      PubDate: 2021-04-18
      DOI: 10.3390/jcs5040113
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 114: Experimental Investigation of
           Instabilities on Different Scales in Compressive Fatigue Testing of
           Composites

    • Authors: Andreas Baumann, Joachim Hausmann
      First page: 114
      Abstract: Compression testing of continuous fiber reinforced materials is challenging, because a great number of competing failure modes and instabilities on different length scales have to be considered. In comparison to tensile testing, the results are more affected by the chosen test set-up. Effects introduced by the test set-up as well as the type of damage in continuous fiber reinforced materials are mainly investigated for quasi-static loading. This is not the case for cyclic compression loading. Neither standardized methods nor a great deal of literature for reference exists. The aim of this work is to increase the understanding by analyzing the potential effects the set-up in fatigue loading might have on the damage for two common testing strategies by fatigue tests, load increase creep tests and supplementary analytical models. The results show that damage modes can be altered by the testing strategy for the investigated woven glass fiber reinforced polyamide 6. The tools both experimentally and analytically provide the basis to choose the correct set-up in future investigations.
      Citation: Journal of Composites Science
      PubDate: 2021-04-20
      DOI: 10.3390/jcs5040114
      Issue No: Vol. 5, No. 4 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 84: Comparison of Specimen Geometries for
           Measuring Through-Thickness Tensile Mechanical Properties of
           Fibre-Reinforced Polymer Composites

    • Authors: Rory Pemberton, Louise Crocker, Matthew Poole, Richard Shaw, Michael Gower
      First page: 84
      Abstract: Engineering design of fibre-reinforced polymer (FRP) composite components requires reliable methods for measuring out-of-plane mechanical properties in the through-thickness (T-T) material direction. Within this work, existing indirect and direct test methods and geometries for measuring T-T tensile properties have been evaluated through experimental testing and finite element analysis (FEA). Experimental testing showed variations, particularly in failure properties, for both indirect (failure strengths from 10–94 MPa) and direct (failure strengths from 48–62 MPa) geometries. Results were shown to be in good agreement with FEA, which also confirmed stress concentration factors. A linear relationship between the magnitude of stress concentration factors and experimentally determined T-T tensile failure strengths was observed for all but one of the direct geometries evaluated. Improved knowledge of stress concentration factors from this work should help instil confidence for industry to use T-T tensile properties determined from these methods.
      Citation: Journal of Composites Science
      PubDate: 2021-03-16
      DOI: 10.3390/jcs5030084
      Issue No: Vol. 5, No. 3 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 85: Determination of Quantum Capacitance of
           Niobium Nitrides Nb2N and Nb4N3 for Supercapacitor Applications

    • Authors: Bharti, Gulzar Ahmed, Yogesh Kumar, Patrizia Bocchetta, Shatendra Sharma
      First page: 85
      Abstract: The density of states and quantum capacitance of pure and doped Nb2N and Nb4N3 single-layer and multi-layer bulk structures are investigated using density functional theory calculations. The calculated value of quantum capacitance is quite high for pristine Nb2N and decent for Nb4N3 structures. However for cobalt-doped unpolarized structures, significant increase in quantum capacitance at Fermi level is observed in the case of Nb4N3 as compared to minor increase in case of Nb2N. These results show that pristine and doped Nb2N and Nb4N3 can be preferred over graphene as the electrode material for supercapacitors. The spin and temperature dependences of quantum capacitance for these structures are also investigated.
      Citation: Journal of Composites Science
      PubDate: 2021-03-20
      DOI: 10.3390/jcs5030085
      Issue No: Vol. 5, No. 3 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 86: Development of Carbon Fiber-Reinforced
           Thermoplastics for Mass-Produced Automotive Applications in Japan

    • Authors: Yi Wan, Jun Takahashi
      First page: 86
      Abstract: The application of carbon fiber-reinforced thermoplastics (CFRTPs) for automotive mass production is attracting increasing attention from researchers and engineers in related fields. This article presents recent developments in CFRTPs focusing on the systematic development of lightweight CFRTP applications for automotive mass production. Additionally, a related national project of Japan conducted at the University of Tokyo is also introduced. The basic development demands, the specific requirements of CFRTPs for lightweight applications in automotive mass production, and the current development status and basic scientific outputs are discussed. The development of high-performance CFRTPs (chopped carbon fiber tape-reinforced thermoplastics (CTTs)) and functional CFRTPs (carbon fiber mat-reinforced thermoplastics (CMTs)) is also introduced. The fabrication process control of CTTs is evaluated, which demonstrates the extreme importance of the mechanical performance. The ultralight lattice, toughened structures, and orientation designable components of CMTs provide a flexible multi-material solution for the proposed applications. Moreover, highly efficient carbon fiber recycling technology is discussed, with recycled carbon fibers exhibiting outstanding compatibility with CFRTPs. A cost sensitivity analysis of carbon fiber and CFRTPs is conducted to guarantee the feasibility and affordability of their application. This article also discusses the trends and sustainability of carbon fiber and CFRTPs usage. The importance of the object-oriented optimal development of CFRTPs is emphasized to efficiently exploit their advantages.
      Citation: Journal of Composites Science
      PubDate: 2021-03-22
      DOI: 10.3390/jcs5030086
      Issue No: Vol. 5, No. 3 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 87: Laser Spot Welding and Electric Contact
           Points Using Copper/Single-Walled Carbon Nanotube Nanocomposite
           Synthesized by Laser Surface Implanting

    • Authors: Jay F. Tu, Nilesh Rajule, Sang Don Mun
      First page: 87
      Abstract: In our previous studies, we have developed a wet process, denoted as laser surface implanting (LSI), to synthesize a copper/single-walled carbon nanotube (Cu–SWCNT) metal nanocomposite. The nanostructure of this Cu–SWCNT composite was shown to contain discernable SWCNT clusters in nanosizes inside the copper matrix. Its hardness could achieve up to three times that of pure copper, verified by micro-hardness and nano-hardness tests. A focus ion beam bombardment test and a plane strain compression test show 2.5 times toughness improvement for the Cu-SWCNT composite. Based on these strength improvements, two potential applications for the Cu-SWCNT nanocomposite are proposed and their feasibilities are verified using specially design test rigs. The first application is related to creating long lasting electric contacts. The result shows that the Cu-SWCNT nanocomposite is highly wear-resistant. The contact area of the simulated electric contacts increases after repeated impact loading, which potentially could lower the contact resistance. The second application is to use the Cu-SWCNT implants as high strength spot weld for joining copper foils. A smaller weld with a higher strength reduces the power requirement of the laser and, consequently, the thermal distortion for higher-dimensional precision. The specially designed test rig for the weld strength characterization is a new contribution, providing a new testing capability for small and non-homogeneous samples not suitable for a standard tensile test machine.
      Citation: Journal of Composites Science
      PubDate: 2021-03-22
      DOI: 10.3390/jcs5030087
      Issue No: Vol. 5, No. 3 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 88: Influence of a Dynamic Consolidation
           Force on In Situ Consolidation Quality of Thermoplastic Composite Laminate
           

    • Authors: Berend Denkena, Carsten Schmidt, Maximilian Kaczemirzk, Max Schwinn
      First page: 88
      Abstract: For achieving high quality of in situ consolidation in thermoplastic Automated Fiber Placement, an approach is presented in this research work. The approach deals with the combination of material pre-heating and sub-ultrasonic vibration treatment. Therefore, this research work investigates the influence of frequency dependent consolidation pressure on the consolidation quality. A simplified experimental setup was developed that uses resistance electrical heating instead of the laser to establish the thermal consolidation condition in a universal testing machine. Consolidation experiments with frequencies up to 1 kHz were conducted. The manufactured specimens are examined using laser scanning microscopy to evaluate the bonding interface and differential scanning calorimetry to evaluate the degree of crystallinity. Additionally, the vibration-assisted specimens were compared to specimens manufactured with static consolidation pressure only. As a result of the experimental study, the interlaminar pore fraction and degree of compaction show a positive dependency to higher frequencies. The porosity decreases from 0.60% to 0.13% while the degree of compaction increases from 8.64% to 12.49% when increasing the vibration frequency up to 1 kHz. The differential scanning calorimetry experiments show that the crystallinity of the matrix is not affected by vibration-assisted consolidation.
      Citation: Journal of Composites Science
      PubDate: 2021-03-22
      DOI: 10.3390/jcs5030088
      Issue No: Vol. 5, No. 3 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 89: Comparative Study of the Reinforcement
           Type Effect on the Thermomechanical Properties and Burning of Epoxy-Based
           Composites

    • Authors: Kamila Salasinska, Mateusz Barczewski, Joanna Aniśko, Aleksander Hejna, Maciej Celiński
      First page: 89
      Abstract: Aramid (AF), glass (GF), carbon (CF), basalt (BF), and flax (FF) fibers in the form of fabrics were used to produce the composites by hand-lay up method. The use of fabrics of similar grammage for composites’ manufacturing allowed for a comprehensive comparison of the properties of the final products. The most important task was to prepare a complex setup of mechanical and thermomechanical properties, supplemented by fire behavior analysis, and discuss both characteristics in their application range. The mechanical properties were investigated using tensile and flexural tests, as well as impact strength measurement. The investigation was improved by assessing thermomechanical properties under dynamic deformation conditions (dynamic mechanical–thermal analysis (DMTA)). All products were subjected to a fire test carried out using a cone calorimeter (CC).
      Citation: Journal of Composites Science
      PubDate: 2021-03-23
      DOI: 10.3390/jcs5030089
      Issue No: Vol. 5, No. 3 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 90: Structural Changes and Their
           Implications in Foamed Flexible Polyurethane Composites Filled with
           Rapeseed Oil-Treated Ground Tire Rubber

    • Authors: Paulina Kosmela, Adam Olszewski, Łukasz Zedler, Paulina Burger, Krzysztof Formela, Aleksander Hejna
      First page: 90
      Abstract: The utilization of post-consumer car tires is an essential issue from an ecological and economic point of view. One of the simplest and the least harmful methods is their material recycling resulting in ground tire rubber (GTR), which can be further applied as fillers for polymer-based composites. Nevertheless, insufficient interfacial interactions implicate the necessity of GTR modification before introduction into polymer matrices. In this study, we investigated the influence of rapeseed oil-assisted thermo-mechanical treatment of GTR using a reactive extrusion process on the processing, structure, and performance of flexible polyurethane/GTR composite foams. Applied modifications affected the processing of polyurethane systems. They caused a noticeable reduction in the average cell size of foams, which was attributed to the potential nucleating activity of solid particles and changes in surface tension caused by the presence of oil. Such an effect was especially pronounced for the waste rapeseed oil, which resulted in the highest content of closed cells. Structural changes caused by GTR modification implicated the enhancement of foams’ strength. Mechanical performance was significantly affected by the applied modifications due to the changes in glass transition temperature. Moreover, the incorporation of waste GTR particles into the polyurethane matrix noticeably improved its thermal stability.
      Citation: Journal of Composites Science
      PubDate: 2021-03-23
      DOI: 10.3390/jcs5030090
      Issue No: Vol. 5, No. 3 (2021)
       
  • J. Compos. Sci., Vol. 5, Pages 91: Effect of Graphene Oxide as a
           Reinforcement in a Bio-Epoxy Composite

    • Authors: Anthony Loeffen, Duncan E. Cree, Mina Sabzevari, Lee D. Wilson
      First page: 91
      Abstract: Graphene oxide (GO) has gained interest within the materials research community. The presence of functional groups on GO offers exceptional bonding capabilities and improved performance in lightweight polymer composites. A literature review on the tensile and flexural mechanical properties of synthetic epoxy/GO composites was conducted that showed differences from one study to another, which may be attributed to the oxidation level of the prepared GO. Herein, GO was synthesized from oxidation of graphite flakes using the modified Hummers method, while bio-epoxy/GO composites (0.1, 0.2, 0.3 and 0.6 wt.% GO) were prepared using a solution mixing route. The GO was characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscope (TEM) analysis. The thermal properties of composites were assessed using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). FTIR results confirmed oxidation of graphite was successful. SEM showed differences in fractured surfaces, which implies that GO modified the bio-epoxy polymer to some extent. Addition of 0.3 wt.% GO filler was determined to be an optimum amount as it enhanced the tensile strength, tensile modulus, flexural strength and flexural modulus by 23, 35, 17 and 31%, respectively, compared to pure bio-epoxy. Improvements in strength were achieved with considerably lower loadings than traditional fillers. Compared to the bio-epoxy, the 0.6 wt.% GO composite had the highest thermal stability and a slightly higher (positive) glass transition temperature (Tg) was increased by 3.5 °C, relative to the pristine bio-epoxy (0 wt.% GO).
      Citation: Journal of Composites Science
      PubDate: 2021-03-23
      DOI: 10.3390/jcs5030091
      Issue No: Vol. 5, No. 3 (2021)
       
 
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