Subjects -> BUILDING AND CONSTRUCTION (Total: 145 journals)
    - BUILDING AND CONSTRUCTION (137 journals)
    - CARPENTRY AND WOODWORK (8 journals)

BUILDING AND CONSTRUCTION (137 journals)                     

Showing 1 - 35 of 35 Journals sorted alphabetically
A+BE : Architecture and the Built Environment     Open Access   (Followers: 30)
Academia : Architecture and Construction     Open Access   (Followers: 1)
ACI Structural Journal     Full-text available via subscription   (Followers: 24)
Advanced Cement Based Materials     Full-text available via subscription   (Followers: 6)
Advances in Building Education     Open Access   (Followers: 7)
Advances in Building Energy Research     Hybrid Journal   (Followers: 12)
Ambiente Construído     Open Access   (Followers: 1)
Anales de Edificación     Open Access   (Followers: 1)
Asian Journal of Civil Engineering     Hybrid Journal   (Followers: 1)
Australasian Journal of Construction Economics and Building     Open Access   (Followers: 10)
Australasian Journal of Construction Economics and Building - Conference Series     Open Access   (Followers: 1)
Baltic Journal of Real Estate Economics and Construction Management     Open Access   (Followers: 3)
Baurechtliche Blätter : bbl     Hybrid Journal  
Bautechnik     Hybrid Journal   (Followers: 3)
BER : Architects and Quantity Surveyors' Survey     Full-text available via subscription   (Followers: 6)
BER : Building and Construction : Full Survey     Full-text available via subscription   (Followers: 11)
BER : Building Contractors' Survey     Full-text available via subscription   (Followers: 2)
BER : Building Sub-Contractors' Survey     Full-text available via subscription   (Followers: 2)
BER : Capital Goods Industries Survey     Full-text available via subscription  
BER : Survey of Business Conditions in Building and Construction : An Executive Summary     Full-text available via subscription   (Followers: 3)
Beton- und Stahlbetonbau     Hybrid Journal   (Followers: 2)
Building & Management     Open Access   (Followers: 3)
Building Acoustics     Hybrid Journal   (Followers: 4)
Building Research Journal     Open Access   (Followers: 4)
Building Services Engineering Research & Technology     Hybrid Journal   (Followers: 3)
Buildings     Open Access   (Followers: 8)
BUILT : International Journal of Building, Urban, Interior and Landscape Technology     Open Access   (Followers: 1)
Built Environment Inquiry Journal     Open Access  
Built-Environment Sri Lanka     Full-text available via subscription  
Case Studies in Construction Materials     Open Access   (Followers: 9)
Cement and Concrete Composites     Hybrid Journal   (Followers: 22)
Cement and Concrete Research     Hybrid Journal   (Followers: 22)
Challenge Journal of Concrete Research Letters     Open Access   (Followers: 7)
Challenge Journal of Concrete Research Letters     Open Access   (Followers: 6)
Change Over Time     Full-text available via subscription   (Followers: 3)
City, Culture and Society     Hybrid Journal   (Followers: 26)
Civil Engineering = Siviele Ingenieurswese     Full-text available via subscription   (Followers: 4)
Clay Technology     Full-text available via subscription  
Concreto y cemento. Investigación y desarrollo     Open Access   (Followers: 1)
Construction Economics and Building     Open Access   (Followers: 4)
Construction Engineering     Open Access   (Followers: 11)
Construction Management and Economics     Hybrid Journal   (Followers: 23)
Construction Research and Innovation     Hybrid Journal   (Followers: 4)
Construction Robotics     Hybrid Journal   (Followers: 1)
Corporate Real Estate Journal     Full-text available via subscription   (Followers: 6)
Dams and Reservoirs     Hybrid Journal   (Followers: 4)
Energy and Built Environment     Open Access   (Followers: 1)
Engineering Project Organization Journal     Hybrid Journal   (Followers: 8)
Environment and Urbanization Asia     Hybrid Journal   (Followers: 4)
Frontiers in Built Environment     Open Access   (Followers: 1)
FUTY Journal of the Environment     Full-text available via subscription   (Followers: 1)
Gaceta Técnica     Open Access  
GISAP : Technical Sciences, Construction and Architecture     Open Access  
Glass Structures & Engineering     Hybrid Journal  
Handbook of Adhesives and Sealants     Full-text available via subscription   (Followers: 2)
HBRC Journal     Open Access   (Followers: 2)
Heritage Matters : The Magazine for New Zealanders Restoring, Preserving and Enjoying Our Heritage     Full-text available via subscription   (Followers: 2)
Housing and Society     Hybrid Journal   (Followers: 4)
HVAC&R Research     Hybrid Journal  
Indoor and Built Environment     Hybrid Journal   (Followers: 3)
Informes de la Construcción     Open Access  
Intelligent Buildings International     Hybrid Journal   (Followers: 1)
International Journal of Advanced Structural Engineering     Open Access   (Followers: 25)
International Journal of Air-Conditioning and Refrigeration     Hybrid Journal   (Followers: 17)
International Journal of Architectural Computing     Full-text available via subscription   (Followers: 7)
International Journal of Built Environment and Sustainability     Open Access   (Followers: 5)
International Journal of Concrete Structures and Materials     Open Access   (Followers: 16)
International Journal of Construction Engineering and Management     Open Access   (Followers: 11)
International Journal of Construction Management     Hybrid Journal   (Followers: 4)
International Journal of Masonry Research and Innovation     Hybrid Journal   (Followers: 1)
International Journal of Protective Structures     Hybrid Journal   (Followers: 6)
International Journal of River Basin Management     Hybrid Journal   (Followers: 1)
International Journal of Structural Stability and Dynamics     Hybrid Journal   (Followers: 7)
International Journal of Sustainable Building Technology and Urban Development     Hybrid Journal   (Followers: 12)
International Journal of Sustainable Built Environment     Open Access   (Followers: 6)
International Journal of Sustainable Construction Engineering and Technology     Open Access   (Followers: 9)
International Journal of Sustainable Real Estate and Construction Economics     Hybrid Journal   (Followers: 2)
International Journal of the Built Environment and Asset Management     Hybrid Journal   (Followers: 4)
International Journal of Ventilation     Full-text available via subscription   (Followers: 1)
International Journal Sustainable Construction & Design     Open Access   (Followers: 3)
Journal for Education in the Built Environment     Open Access   (Followers: 3)
Journal of Architecture, Planning and Construction Management     Open Access   (Followers: 11)
Journal of Asian Architecture and Building Engineering     Open Access  
Journal of Building Construction and Planning Research     Open Access   (Followers: 10)
Journal of Building Engineering     Hybrid Journal   (Followers: 4)
Journal of Building Materials and Structures     Open Access   (Followers: 3)
Journal of Building Pathology and Rehabilitation     Hybrid Journal  
Journal of Building Performance Simulation     Hybrid Journal   (Followers: 7)
Journal of Civil Engineering and Construction Technology     Open Access   (Followers: 16)
Journal of Civil Engineering and Management     Open Access   (Followers: 9)
Journal of Computational Acoustics     Hybrid Journal   (Followers: 5)
Journal of Computing in Civil Engineering     Full-text available via subscription   (Followers: 22)
Journal of Construction Engineering     Open Access   (Followers: 9)
Journal of Construction Engineering, Technology & Management     Full-text available via subscription   (Followers: 5)
Journal of Construction Project Management and Innovation     Full-text available via subscription   (Followers: 8)
Journal of Green Building     Full-text available via subscription   (Followers: 10)
Journal of Legal Affairs and Dispute Resolution in Engineering and Construction     Full-text available via subscription   (Followers: 5)
Journal of Sustainable Cement-Based Materials     Hybrid Journal  
Journal of Sustainable Design and Applied Research in Innovative Engineering of the Built Environment     Open Access   (Followers: 2)
Journal of the South African Institution of Civil Engineering     Open Access   (Followers: 2)
Journal of Transport and Land Use     Open Access   (Followers: 25)
Landscape History     Hybrid Journal   (Followers: 14)
Materiales de Construcción     Open Access   (Followers: 2)
Mauerwerk     Hybrid Journal  
Modular and Offsite Construction (MOC) Summit Proceedings |     Open Access   (Followers: 4)
Naval Engineers Journal     Hybrid Journal   (Followers: 2)
Open Construction & Building Technology Journal     Open Access  
Organization, Technology and Management in Construction     Open Access  
PARC Pesquisa em Arquitetura e Construção     Open Access  
Proceedings of the Institution of Civil Engineers - Forensic Engineering     Hybrid Journal  
Proceedings of the Institution of Civil Engineers - Urban Design and Planning     Hybrid Journal   (Followers: 13)
Revista ALCONPAT     Open Access   (Followers: 2)
Revista de la Construcción     Open Access  
Revista de Urbanismo     Open Access   (Followers: 2)
Revista Hábitat Sustenable     Open Access   (Followers: 1)
Revista IBRACON de Estruturas e Materiais     Open Access   (Followers: 1)
Revista Ingenieria de Construcción     Open Access   (Followers: 1)
Revista INVI     Open Access  
RILEM Technical Letters     Open Access  
Room One Thousand     Open Access  
Ruang-Space: Jurnal Lingkungan Binaan (Journal of The Built Environment)     Open Access  
Russian Journal of Construction Science and Technology     Open Access  
Science and Engineering of Composite Materials     Open Access   (Followers: 62)
Science and Technology for the Built Environment     Hybrid Journal   (Followers: 1)
Steel Construction - Design and Research     Hybrid Journal   (Followers: 5)
Stroitel’stvo : Nauka i Obrazovanie     Open Access  
Structural Concrete     Hybrid Journal   (Followers: 10)
Structural Mechanics of Engineering Constructions and Buildings     Open Access   (Followers: 2)
Sustainable Buildings     Open Access   (Followers: 1)
Sustainable Cities and Society     Hybrid Journal   (Followers: 23)
Technology|Architecture + Design     Hybrid Journal  
Terrain.org : A Journal of the Built & Natural Environments     Free   (Followers: 3)
The Historic Environment : Policy & Practice     Hybrid Journal   (Followers: 5)
The IES Journal Part A: Civil & Structural Engineering     Hybrid Journal   (Followers: 6)
Tidsskrift for boligforskning     Open Access  
YBL Journal of Built Environment     Open Access  
Zeitschrift für Miet- und Raumrecht     Hybrid Journal  

           

Similar Journals
Journal Cover
International Journal of Structural Stability and Dynamics
Journal Prestige (SJR): 1.005
Citation Impact (citeScore): 2
Number of Followers: 7  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0219-4554 - ISSN (Online) 1793-6764
Published by World Scientific Homepage  [119 journals]
  • Simultaneous Online Damage Detection and Vibration Control of Structures
           Using Synchronization and Semi-Active Control
    • Authors: Mahdi Moradmand, Fereidoun Amini, Pedram Ghaderi
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, a smart structure is developed by integrating a semi-active control strategy with an online synchronization-based damage detection method. In this algorithm, the structural damages are identified in real-time with the synchronization-based method using displacement and velocity measurements of the structure. Then, a fuzzy logic controller is applied for determination of the control forces according to the occurrence of damages. A five-story linear shear building equipped with magneto-rheological (MR) dampers is studied numerically to verify the performance and efficiency of the proposed integrated method for both damage detection and vibration suppression. One damage scenario and four earthquake records are used for such purpose. Results demonstrate that the proposed algorithm has the capability of identifying structural damages satisfactorily while exerting suitable control forces to compensate for the damages occurrence and mitigating the dynamic responses of the structure. Furthermore, it is shown that in comparison with the long-established method of only vibration control, the total energy consumption is significantly reduced, an issue of concern in optimal control of structures.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-01-20T08:00:00Z
      DOI: 10.1142/S0219455421500383
       
  • Time-Varying Parameter Identification of Bridges Subject to Moving
           Vehicles Using Ridge Extraction Based on Empirical Wavelet Transform
    • Authors: Jiantao Li, Jian Guo, Xinqun Zhu
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      For a vehicle moving over a bridge, the vehicle-bridge interaction (VBI) embraces the time-varying modal parameters of the system. The identification of non-stationary characteristics of bridge responses due to moving vehicle load is important and remains a challenging task. A new method based on the improved empirical wavelet transform (EWT) along with ridge detection of signals in time-frequency representation (TFR) is proposed to estimate the instantaneous frequencies (IFs) of the bridge. Numerical studies are conducted using a VBI model to investigate the time-varying characteristics of the system. The effects of the measurement noise, road surface roughness and structural damage on the bridge IFs are investigated. Finally, the dynamic responses of an in-situ cable-stayed bridge subjected to a passing vehicle are analyzed to further explore the time varying characteristics of the VBI system. Numerical and experimental studies demonstrate the feasibility and effectiveness of the proposed method on the IF estimation. The identified IFs reveal important time-varying characteristics of the bridge dynamics that is significant to evaluating the actual performance of operational bridges in operation and may be used for structural health assessment.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-01-18T08:00:00Z
      DOI: 10.1142/S0219455421500462
       
  • Generative Adversarial Networks-Based Stochastic Approach to the Modeling
           of Individual Jumping Loads
    • Authors: Shuqian Duan, Jiecheng Xiong, Hui Qian
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Features of jumping loads are essentially high-dimensional random variables but have been simplistically modeled owing to the lack of proper mathematical tools. Generative adversarial networks (GANs) in conjunction with deep learning technology are adopted herein for modeling the jumping loads. Conditional GANs (CGANs) combined with Wasserstein GANs (WGANs) with gradient penalty (WGANs-GP) are adopted in the impulse modeling, where a multi-layer perceptron and a convolutional neural network are employed for the discriminator and generator, respectively. As for the impulse amplitude sequence and interval sequence modeling, similar CGANs combined with WGANs-GP are adopted, where recurrent neural networks are employed for both the generator and discriminator. A large amount of measured individual jumping loads are utilized in training GANs to ensure the generated samples can simulate the real ones well. After training, the individual jumping loads are simulated by connecting the generated impulse samples, based on the generated impulse amplitude sequence samples and interval sequence samples. The simulated jumping loads can be used to assess the vibration performance of assembly structures, such as grandstands, concert halls, and gym floors. Moreover, the established GANs can be extended to the modeling of other stochastic dynamic excitations.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-01-18T08:00:00Z
      DOI: 10.1142/S0219455421500474
       
  • Experimental Study of the Effect of Proximity between Adjacent Buildings
           on their Dynamic Response
    • Authors: Gonzalo Barrios, Tam Larkin, Nawawi Chouw
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Most of the experimental works on adjacent structures consider a short distance between them to analyze the interaction. Additionally, the majority of these studies focus on changes in the dynamic response of the buildings (e.g. acceleration, lateral displacement, or rocking) assuming that the fundamental frequency and the damping of the structures remain the same as those for the stand-alone case. This work intends to reveal the effect of distance on the interaction between adjacent structures and the effect of neighboring buildings on the dynamic properties of a structure. This was achieved by studying the dynamic response of single degree-of-freedom (SDOF) structures in a laminar box filled with sand sitting on a shake table. This study initially addressed the attenuation of the acceleration through the soil with the distance considering the structures at different distances. The second part of the study considers multiple configurations of adjacent structures to estimate the influence of the number of neighbors on the fundamental frequency and damping ratio of a subject building. An increasing fundamental frequency with an increasing number of participating structures was observed. An equation to estimate the influence of the number of neighboring buildings on the fundamental frequency of the subject structure is proposed. For the damping ratio, a considerable influence of the soil was observed. The lowest damping was obtained for an intermediate number of structures.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-01-18T08:00:00Z
      DOI: 10.1142/S0219455421500486
       
  • Nonlinear Behaviors of Spinning Pipes Conveying Fluid with Pulsation
    • Authors: Morteza Khoshroo, Mojtaba Eftekhari
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Bifurcation analysis is conducted to investigate the dynamics of a spinning pipe conveying fluid with pulsation. The partial differential equations of the system are obtained by considering the nonlinearity in curvature and inertia. They are then discretized to the ordinary differential equations by means of the Galerkin expansion so that the primary and combination resonance conditions are imposed to the system. Moreover, the multiple scales method is utilized to solve the resultant equations, and the stability of the equilibrium points of the system is determined through the continuation method. The equilibrium solutions are also examined by the numerical integration, by which the existence of double jump, saddle node and Hopf bifurcations are demonstrated for different values of the fluid velocity.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-01-18T08:00:00Z
      DOI: 10.1142/S0219455421500504
       
  • Vibration-based Monitoring for Transverse Cooperative Working Performance
           of Assembled Concrete Multi-Girder Bridge: System Design, Implementation
           and Preliminary Application
    • Authors: Zhaoyuan Xu, Danhui Dan, Lu Deng
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The hinge joints of the assembled concrete multi-girder bridge (ACMGB) are the main components of transverse transmission of loads and the decline of their transmission capacity would lead to the degradation of the transverse cooperative working performance (TCWP) of the multi-beam system. As the key working performance of this kind of bridges, its severe degradation would result in the single-girder-bearing phenomenon inducing bridge collapse. In order to detect TCWP degradation timely, this paper proposes a vibration-based monitoring scheme of the ACMGB, where structural vibration information are collected by accelerometers and dynamic strain guages at the bottom of girders in mid-span. These monitoring data are then used for identifying transverse mode shape of the multi-beam system and its derivated index in order to evaluate TCWP. This scheme has been implemented on three adjacent ACMGBs in Tongji Road Viaduct and the preliminary analysis of monitoring data proves the effectiveness and rationality of the monitoring scheme proposed in this paper, which has the potential of the TCWP evaluation.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-01-09T08:00:00Z
      DOI: 10.1142/S0219455421500437
       
  • Free Vibrations of Steel–Concrete Composite Beams by the Dynamic
           Direct Stiffness Method
    • Authors: Qikai Sun, Nan Zhang, Xiao Liu, Xiaoyan Tao
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      A new dynamic direct stiffness method for analyzing the natural vibration characteristics of steel–concrete composite beams (SCCBs) is proposed, which considers the effect of partial interaction between the interface of the concrete slab and steel beam. The advantage of the method is that exact solutions can be obtained due to no introduction of approximated displacement and/or force fields in the derivation. Besides, the method is especially useful for the dynamic analysis of SCCBs with axial variable stiffness under four common boundary conditions. The proposed method is validated by comparing with the theoretical and experimental results available in the literature. Finally, the effects of different boundary conditions, shear connection, cross-sectional stiffness ratio, and other parameters upon the frequencies of the beam are discussed in detail.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-01-09T08:00:00Z
      DOI: 10.1142/S0219455421500498
       
  • Stability of Layered Structures with Hybridized Configuration by Means of
           a Reddy-Type Higher-Order Finite Element Formulation
    • Authors: Zhen Wu, Jie Zhou, Zhengliang Liu, Rui Ma, Xiaohui Ren
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      To make use of the merit of designability, each lamina in layered structures may possess diverse materials and geometry to realize specific application. For the hybridized structures, geometry and material properties relative to the middle surface are generally unsymmetrical, which have a significant impact on stability. Some models might lose capability to deal with such issues, so that these issues are less reported. Within the developed models, Reddy’s model possesses merit of simplicity and efficiency, so a Reddy-type higher-order zig-zag model is constructed by utilizing the proposed zig-zag function (ZZF). Instead of the standard finite element formulation using the principle of minimum potential energy, the three-field Hu–Washizu (HW) mixed variational principle is employed to acquire the finite element formulation which can meet the harmonious conditions of transverse shear stress at the interface of adjacent layers. By investigating buckling behaviors of hybridized structures, performance of the proposed finite element formulation is appraised by comparing with the results obtained from the three-dimensional (3D) model as well as other models. Effect of boundary conditions (BCs), material properties, and span-to-thickness ratio on the buckling loads is also studied in detail. Numerical results show that buckling loads of hybridized structures are significantly impacted by the chosen parameters. The results acquired from proposed model are in very good agreement with those obtained from the layerwise (LW) model and the 3D finite element results.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-01-06T08:00:00Z
      DOI: 10.1142/S0219455421500450
       
  • Preface: IJSSD 20th Anniversary Special Issue
    • Authors: C. M. Wang
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.

      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-18T08:00:00Z
      DOI: 10.1142/S0219455420020034
      Issue No: Vol. 20, No. 13 (2020)
       
  • Stability of Thin Web Composite Cantilever Beams of Random Lamination
    • Authors: Hayder A. Rasheed, Habiburrahman Ahmadi, Abdul H. Halim
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      This study addresses the analytical treatment of a closed-form buckling equation for lateral-torsional stability of thin web composite cantilever beams under mid-height tip force. The beam is composed of random ply fiber orientations. Classical lamination theory is embedded into the Vlasov plate formulation to make up the framework of the analytical treatment. A closed-form solution is realized when an innovative dimensional reduction is extended to the 3D constitutive stiffness matrix. This was made possible through a two-step process in which the shear strain, lateral curvature, and twisting curvature are retained first. By condensing the shear strain variable, effective lateral, torsional, and coupling stiffness terms were formulated. Applying the equilibrium conditions in the deformed configuration, two differential equations are obtained in terms of the lateral curvature and twisting angle. Eliminating the lateral curvature, the twisting angle differential equation with nonconstant coefficients is generated. This equation is solved using a hybrid numerical-analytical approach yielding an analytical buckling expression. Finite element results are generated to verify the accuracy of the buckling load predictions indicating very good correlation with the buckling equation results regardless of the random lamination applied.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-03T08:00:00Z
      DOI: 10.1142/S0219455420410163
      Issue No: Vol. 20, No. 13 (2020)
       
  • Estimation of Seismic Damage Induced by Near- and Far-Fault Earthquakes
           Using Modified Equivalent Linearization Method of Mid-Rise RC Buildings
    • Authors: Chien-Kuo Chiu, Lorddy Z. Nugroho, Wen-I. Liao
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      For the seismic design of a mid-rise reinforced concrete (RC) building considering the damage control, the main purpose of this work is to propose a simplified method that can be used to estimate the damage index or damage state induced by the near-fault and far-fault earthquakes. In addition to the maximum deformation response, the hysteretic energy dissipation induced the earthquakes is also considered in the damage index quantification based on the modified equivalent linearization method (MELM). Based on the damage index model in terms of the maximum deformation response and hysteretic energy dissipation under an earthquake, this work provides a convenient method by which an engineer can determine the damage-controlling minimal ductility requirement to ensure that the damage index remains under a specified value. For a mid-rise RC building structure, an engineer can also apply the simplified formula proposed in this work to obtain the damage-controlling yielding strength for a specified ductility capacity.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-03T08:00:00Z
      DOI: 10.1142/S0219455420410175
      Issue No: Vol. 20, No. 13 (2020)
       
  • Effect of Crack Closure on Magnitude of Modulated Wave
    • Authors: Sang Eon Lee, Jung-Wuk Hong
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      Fatigue cracks generated by repeated loads cause structural failures. Such cracks grow continuously and at an increasing speed owing to the concentration of stresses near the crack tips. Therefore, the early detection of fatigue cracks is imperative in the field of structural-health monitoring for the safety of structures exposed to dynamic loading. In particular, the detection of those cracks subjected to compression is known as a challenging problem in the nondestructive inspection area. The nonlinear ultrasonic modulation technique is effective for the detection of microcracks smaller than the size of a wavelength because this technique uses the deformation of waves passing through the crack surfaces. However, the technique has not been thoroughly verified for detecting cracks subjected to external forces. In this study, nonlinear ultrasonic modulation tests are performed on two types of crack specimens under compressive forces. The results show that in fatigue-cracked specimens, the cracks can be detected using modulated waves even under strong compressions. With artificial cracks, buckling occurs at a relatively low compression, and the amounts of modulated waves rapidly increase due to the bending of the specimen before buckling failure takes place. In this study, the crack detection methodology under compression is proposed and experimentally verified. The proposed method might be beneficial to find cracks under compression in various structural components.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-03T08:00:00Z
      DOI: 10.1142/S0219455420410187
      Issue No: Vol. 20, No. 13 (2020)
       
  • Mechanical Analysis of Functionally Graded Porous Structures: A Review
    • Authors: Helong Wu, Jie Yang, Sritawat Kitipornchai
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      Functionally graded porous structures (FGPSs), characterized by a continuous spatial gradient in both porosity and material properties, have been considered as the new generation lightweight structures. Research activities on FGPSs have grown rapidly in recent years. This paper is devoted to review the existing research works on FGPSs and to highlight the important advances in this emerging area. It consists of: (i) a brief introduction of porous materials and Functionally graded porous materials (FGPMs); (ii) an elaboration of the key factor and micromechanical models related to material properties of FGPMs; (iii) a comprehensive review of mechanical analysis of FGPSs; (iv) a detailed discussion of the main challenges and future research directions; (v) a conclusion.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-23T08:00:00Z
      DOI: 10.1142/S0219455420410151
      Issue No: Vol. 20, No. 13 (2020)
       
  • Uncertainty Updating of Finite Element Models Using Interval Analysis
    • Authors: Deshan Shan, Y. H. Chai, Hao Dong, Zhonghui Li
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      Uncertainties in structural parameters and measurements can be accounted for by incorporating interval analysis into the updating scheme of finite element models using a response-surface function. To facilitate the interval arithmetic operation, two different strategies are proposed in this paper to transform the response-surface function into a corresponding interval response-surface function. These strategies minimize the inherent interval overestimation that can arise from the variable dependency of the surrogate model. In the first strategy, the natural extension and centered-form extension methods are used to mitigate the interval overestimation of the surrogate model, which may or may not contain interaction terms. In the second strategy, the natural extensión method is also adopted to realize the interval transformation of the surrogate model containing interaction terms but an affine arithmetic is further introduced to minimize the interval overestimation. To demonstrate the efficacy of the proposed method, model parameters are determined from an instrumented model of a cable-stayed bridge tested on a shaking table. Results show that the proposed updating method is feasible and effective for applications to finite element models of complex bridge structures.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-14T07:00:00Z
      DOI: 10.1142/S0219455420410126
      Issue No: Vol. 20, No. 13 (2020)
       
  • Effect of Soil–Structure Interaction on Nonlinear Dynamic Response of
           Reinforced Concrete Structures
    • Authors: Christos Mourlas, Neo Khabele, Hussein A. Bark, Dimitris Karamitros, Francesca Taddei, George Markou, Manolis Papadrakakis
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      Investigating the nonlinear dynamic response of reinforced concrete (RC) structures is of significant importance in understanding the expected behavior of these structures under dynamic loading. This becomes more crucial during the design of new or the assessment of the existing RC structures that are located in seismically active areas. The numerical simulation of this problem through the use of detailed 3D modeling is still a subject that has not been investigated thoroughly due to the significant challenges related to numerical instabilities and excessive computational demand, especially when the soil–structure interaction (SSI) phenomenon is accounted for. This study aims at presenting a nonlinear simulation tool to investigate this numerically cumbersome problem in order to provide further inside into the SSI effect on RC structures under nonlinear dynamic loading conditions. A detailed 3D numerical model of full-scale RC structures considering the SSI effect through modeling the nonlinear frame and soil domain is performed and discussed herein. The constructed models are subjected to dynamic loading conditions and an elaborate investigation is presented considering different type of structures, material properties of soil domains and depths. The RC structures and the soil domains are modeled through 8-noded hexahedral isoparametric elements, where the steel bar reinforcement of concrete is modeled as embedded beam and truss finite elements. The Ramberg–Osgood constitutive law was used for modeling the soil domain. It was shown that the SSI effect can significantly increase the flexibility of the system, altering the nonlinear dynamic response of the RC frames causing local damages that are not observed when the fixed-base model is analyzed. Furthermore, it was found that the structures founded on soft soil developed larger base-shear compared to the fixed-base model which is attributed to resonance phenomena connected to the SSI effect and the imposed accelerograms.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-14T07:00:00Z
      DOI: 10.1142/S0219455420410138
      Issue No: Vol. 20, No. 13 (2020)
       
  • Elastic In-Plane Buckling of Funicular Arches
    • Authors: W. H. Pan, C. M. Wang
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      Buckling loads of arches could be significantly affected by the assumptions made on the load behavior during buckling. For a funicular arch whose centerline coincides with the compression line, we may consider two types of load behaviors based on how the line of load action shifts during buckling. This paper presents the governing differential equations for the elastic in-plane buckling problem of funicular circular arches under uniform radial pressure based on the two different load behavior assumptions, as well as analytical and numerical methods for analysis. For the analytical method, buckling criteria of rotationally-restrained ended circular arches with an internal rotational spring are formulated by using the general solution of the governing differential equation. For the numerical method, the Hencky bar-chain model (HBM) and its simple matrix formulations for general funicular arches are established. The buckling loads and mode shapes of funicular circular arches are solved by using HBM and verified against exact solutions obtained from the analytical method. For funicular catenary arches and parabolic arches, the buckling load solutions by HBM with various number of segments are also obtained and compared with the solutions presented by the previous researchers.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-13T07:00:00Z
      DOI: 10.1142/S021945542041014X
      Issue No: Vol. 20, No. 13 (2020)
       
  • The Evolving Basis for the Design of Light Gauge Steel Systems
    • Authors: Pinelopi Kyvelou, David A. Nethercot, Nicolas Hadjipantelis, Constantinos Kyprianou, Leroy Gardner
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      The importance of allowing for the many different types of structural interaction that have an effect on the performance of light gauge members when used in practical situations is emphasized. A distinction is drawn between internal interactions involving the various plate elements of the steel profiles and external interactions involving the other components in the system. Although full-scale testing of representative systems can capture this behavior, the costs involved make this an impractical general basis for design; codified methods generally consider only isolated plates within members and isolated members within systems, thereby neglecting the potentially beneficial effects of both forms of interaction. Properly used, modern methods of numerical analysis offer the potential to systematically allow for both forms of interaction — provided the numerical models used have been adequately validated against suitable tests. The use of such an approach is explained and illustrated for three commonly used structural systems: roof purlins, floor beams, and columns in stud walls. In each case, it is shown that, provided sufficient care is taken, the numerical approach can yield accurate predictions of the observed test behavior. The subsequently generated large portfolio of numerical results can then provide clear insights into the exact nature of the various interactions and, thus, form the basis for more realistic design approaches that are both more accurate in their predictions and which lead to more economic designs. Building on this, modifying existing arrangements so as to yield superior performance through specific modifications is now possible. Two such examples, one in which improved interconnection between the components in a system is investigated and a second in which prestressing is shown to provide substantial enhancement for relatively small and simple changes, are presented.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-10T07:00:00Z
      DOI: 10.1142/S0219455420410084
      Issue No: Vol. 20, No. 13 (2020)
       
  • Programmable Spiral and Helical Deformation Behaviors of Hydrogel-Based
           Bi-Material Beam Structures
    • Authors: Rong Huang, Yiheng Xue, Zhengjie Li, Zishun Liu
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      Soft materials possess magnificent properties which could be harnessed for different potential applications. Compared to other soft materials, hydrogels have some unique advantages which can be used in the shape deformation or shape transformation of structures. This paper aims to investigate the deformation mechanisms of hydrogel-based bi-material beam structures and study the non-uniform geometric effects on the shape transformation including programmable scroll and helical deformations. With a sloped thickness design, the structures could be transformed from an initial quasi-2D beam configuration into some other 2D self-scroll and 3D self-helical configurations. From the hydrogel material model, a modified deformation formula for bi-material beam structures based on the framework of the classical beam theory has been developed to predict the shape morphing behaviors. The relationship between the curvature and the mismatch strain is derived in its explicit form and the theoretical results are verified through several numerical simulations. Furthermore, experiments are carried out to demonstrate the design principles for reconfigurable bi-material beam structures and the experiments show that the structures tend to deform similarly to that predicted by the analytical models. The presented work could provide guidance for future applications of responsive hydrogel-based bi-material beam structures such as in soft actuators and soft robots.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-05T07:00:00Z
      DOI: 10.1142/S0219455420410102
      Issue No: Vol. 20, No. 13 (2020)
       
  • Viscoelasticity of Fractional Order: New Restrictions on Constitutive
           Equations with Applications
    • Authors: Teodor M. Atanacković, Marko B. Janev, Stevan Pilipović, Dora Seleši
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      In this paper, we analyze the restrictions on the coefficients in the constitutive equations of linear Viscoelasticity that follow from the Second Law of Thermodynamics under isothermal conditions. Especially, we analyze the constitutive equations in which fractional derivatives of real and complex order appear. We present the conditions that follow after application of the Bochner–Schwartz theorem. Conditions derived here, representing in certain cases a weak form of the Second law of Thermodynamics, are more general (weaker) than the classical Bagley–Torvik conditions widely used in Viscoelasticity Theory. Several examples that illustrate the theory are presented.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-05T07:00:00Z
      DOI: 10.1142/S0219455420410114
      Issue No: Vol. 20, No. 13 (2020)
       
  • GBT Analysis of Steel-Concrete Composite Beams: Recent Developments
    • Authors: Rodrigo Gonçalves, Dinar Camotim, David Henriques
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      This paper reports the most recent developments concerning Generalized Beam Theory (GBT) formulations, and corresponding finite element implementations, for steel-concrete composite beams. These formulations are able to perform the following types of analysis: (i) materially nonlinear analysis, to calculate the beam load-displacement response, up to collapse, including steel plasticity, concrete cracking/crushing and shear lag effects, (ii) bifurcation (linear stability) analysis, to obtain local/distortional bifurcation loads and buckling mode shapes of beams subjected to negative (hogging) bending, accounting for shear lag and concrete cracking effects and (iii) long-term service analysis including creep, cracking and arbitrary cross-section deformation (which includes shear lag) effects. The potential (computational efficiency and accuracy) of the proposed GBT-based finite elements is illustrated through several numerical examples. For comparison purposes, results obtained with standard finite strip and shell/brick finite element models are provided.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-09-22T07:00:00Z
      DOI: 10.1142/S0219455420410072
      Issue No: Vol. 20, No. 13 (2020)
       
  • Medium-Frequency Vibration Analysis of Timoshenko Beam Structures
    • Authors: Yichi Zhang, Bingen Yang
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      Medium-frequency (mid-frequency) vibration analysis of complex structures plays an important role in automotive, aerospace, mechanical, and civil engineering. Flexible beam structures modeled by the classical Euler–Bernoulli beam theory have been widely used in various engineering problems. A kinematic hypothesis made in the Euler–Bernoulli beam theory is that the plane sections of a beam normal to its neutral axis remain planes after the beam experiences bending deformation, which neglects shear deformation. However, previous investigations found out that the shear deformation of a beam (even with a large slenderness ratio) becomes noticeable in high-frequency vibrations. The Timoshenko beam theory, which describes both bending deformation and shear deformation, would naturally be more suitable for medium-frequency vibration analysis. Nevertheless, vibrations of Timoshenko beam structures in a medium frequency region have not been well studied in the literature. This paper presents a new method for mid-frequency vibration analysis of two-dimensional Timoshenko beam structures. The proposed method, which is called the augmented Distributed Transfer Function Method (DTFM), models a Timoshenko beam structure by a spatial state-space formulation in the [math]-domain. The augmented DTFM determines the frequency response of a beam structure in an exact and analytical form, in any frequency region covering low, middle, or high frequencies. Meanwhile, the proposed method provides the local information of a beam structure, such as displacement, shear deformation, bending moment and shear force at any location, which otherwise would be very difficult with energy-based methods. The medium-frequency analysis by the augmented DTFM is validated in numerical examples, where the efficiency and accuracy of the proposed method is demonstrated. Also, the effects of shear deformation on the dynamic behaviors of a beam structure at medium frequencies are examined through comparison of the Timoshenko beam and Euler–Bernoulli beam theories.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-09-22T07:00:00Z
      DOI: 10.1142/S0219455420410096
      Issue No: Vol. 20, No. 13 (2020)
       
  • Estimating Exceedance Probabilities of Railway Bridge Vibrations in the
           Presence of Random Rail Irregularities
    • Authors: Patrick Salcher, Christoph Adam
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      This contribution addresses the estimation of exceedance probabilities of the dynamic random response of railway bridges subjected to high-speed trains in the presence of random rail irregularities. The random nature of the irregular rail track is described by a spatial ergodic stochastic process, and consequently the dynamic bridge response becomes a stochastic process in time with generally unknown distributions. Using numerical simulation methods, the response thresholds for bridge deflection and acceleration are estimated to obtain small exceedance probabilities. Combining these limits with the response at perfect rail geometry provides an estimate of the dynamic response amplification due to random rail irregularities. This is in line with the semi-probabilistic safety concept of modern civil engineering, where critical response thresholds for structures are associated with small exceedance probabilities. It is shown that modeling the maximum bridge deflection as a normally distributed random variable with parameters fitted to the results of a Monte Carlo simulation with small sample size is a computationally efficient approach for estimating the amplified deflection. In contrast, the random maximum bridge acceleration is better captured by a lognormal distribution. As an efficient alternative, the subset simulation method provides accurate predictions for very small exceedance probabilities. If the amplitudes of the rail irregularities at discrete spatial coordinates along the rail axis are considered as random variables, the stability of subset simulation increases.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-09-04T07:00:00Z
      DOI: 10.1142/S0219455420410059
      Issue No: Vol. 20, No. 13 (2020)
       
  • Random Response of Multi-Segment Beam May Exceed Response of Homogeneous
           Counterparts by Order of Magnitude
    • Authors: T. Fang, I. Elishakoff, C. Jiang
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      This paper investigates the dynamic properties of an inhomogeneous, Bernoulli–Euler multi-segment beam composed of different materials. To the best of knowledge of the authors, the problem of random vibrations of beams composing of different chunks of the beams, namely, strong and weak parts, has not been studied in the literature. In this paper, exact solution of the natural frequencies and associated mode shapes of the multi-segment Bernoulli–Euler beam are obtained using Krylov–Duncan functions, followed by free, forced, and random vibration analyses using the normal mode method. Special emphasis is placed on two special configurations of multi-segment beam, namely, the ‘rigid-soft-rigid beam’ (RSR beam) and ‘soft-rigid-soft beam’ (SRS beam) as simplest manifestations of the multi-chunked structures. Some remarkable properties exhibited by the dynamic response of multi-segment beam are demonstrated through this work, which may be of considerable engineering significance, and could not have been anticipated in advance, especially quantitatively.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-09-02T07:00:00Z
      DOI: 10.1142/S0219455420410060
      Issue No: Vol. 20, No. 13 (2020)
       
  • State-of-the-Art of Vehicle-Based Methods for Detecting Various Properties
           of Highway Bridges and Railway Tracks
    • Authors: Y. B. Yang, Zhi-Lu Wang, Kang Shi, Hao Xu, Y. T. Wu
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      The vehicle scanning method (VSM), an indirect approach for bridge measurement, has attracted intensive attention since it was proposed. By this method, a moving test vehicle is employed to detect the “mechanical” properties of the bridge, e.g. frequencies, mode shapes, damages, etc., utilizing the interaction between the two substructures. Compared with the conventional direct approach that requires quite a few sensors and data loggers to be fitted on the bridge, the advantage of the VSM is obvious: mobility, economy, and efficiency. As for railways, the broader vehicle-based techniques have long been used to detect the “geometrical” properties of the track, such as track profiles and rail conditions. Relatively little use has been made of the interaction between the moving vehicle/train and the track/bridge. This paper is a state-of-the-art report of the VSM’s applications to highway bridges and the vehicle-based techniques to railway tracks. It starts with a summary of the pioneering works by Yang and co-workers on the VSM. Then, the applications of the techniques to highway bridges and railway tracks will be separately reviewed. Conclusions will be made, along with future research directions, at the end of the paper.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-08-31T07:00:00Z
      DOI: 10.1142/S0219455420410047
      Issue No: Vol. 20, No. 13 (2020)
       
  • Frequency Comparison Function Method for Real-Time Identification of
           Breathing Crack at Welding Joint
    • Authors: Xin Wang, Nan Wu, Quan Wang
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      In this research, the frequency comparison function (FCF) method is proposed and studied to realize high-sensitive real-time crack identification at the welding joint area for a beam-type structure. This method is derived from the frequency response function (FRF). During FCF, we use the response signal collected from the designated point of the structure instead of the excitation. The standard deviation of the FCF amplitude curve is calculated to detect and evaluate the possible crack and its induced vibration perturbations afterward. Vibration responses are simulated in ANSYS by the use of the finite element analysis of a welded beam structure, and these signals are then analyzed with the FCF algorithm. It is concluded that FCF is an efficient method for breathing crack identification and can be easily applied under different excitation conditions, including harmonic and random ones. Meanwhile, FCF can be applied without any pre-processing algorithms such as filtering and smoothing. So, it can be used for real-time crack identification. By combining the FCF with the smart coating sensor composed of piezoelectric layers, the crack identification with high sensitivity is realized. The crack is detectable at its very early stage (starting from 3% of the beam thickness). Experimental studies under harmonic and random excitations are processed, and the results prove high sensitivity and feasibility of the proposed crack detection method.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-08-12T07:00:00Z
      DOI: 10.1142/S0219455420410011
      Issue No: Vol. 20, No. 13 (2020)
       
  • A Comparative Study of Implicit and Explicit Composite Time Integration
           Schemes
    • Authors: Wooram Kim, J. N. Reddy
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      In this paper, a number of recently proposed implicit and explicit composite time integration schemes are reviewed and critically evaluated. To give suitable guidelines of using them in practical transient analyses of structural problems, numerical performances of these schemes are compared through illustrative examples. Meaningful insights into computational aspects of the composite schemes are also provided. In the discussion, the role of the splitting ratio of the recent composite schemes is also investigated through a different point of view, and similarities and differences of various composite schemes are also studied. It is shown that the explicit composite scheme proposed recently by the authors can noticeably increase the efficiency and the accuracy of linear and nonlinear transient analyses when compared with other well-known composite schemes.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-08-08T07:00:00Z
      DOI: 10.1142/S0219455420410035
      Issue No: Vol. 20, No. 13 (2020)
       
  • Modal Analysis of a Bridge During High-Speed Train Passages by Enhanced
           Variational Mode Decomposition
    • Authors: Xiao-Mei Yang, Chun-Xu Qu, Ting-Hua Yi, Hong-Nan Li, Hua Liu
      Abstract: International Journal of Structural Stability and Dynamics, Volume 20, Issue 13, December 2020.
      Modal analysis of bridge under high-speed trains is essential to the design and health monitoring of bridge, but it is difficult to be implemented since the vehicle–bridge interaction (VBI) effect is involved. In this paper, the time–frequency analysis technique is performed on the non-stationary train-induced bridge responses to estimate the frequency variations. To suppress the interference terms in time–frequency analysis but preserve the time-variant characteristics of responses, the enhanced variational mode decomposition (VMD) is proposed, which is used to decompose the train-induced dynamic response into many of envelope-normalized intrinsic mode functions (IMFs). Then the short-time Fourier transform is applied to observe the time–frequency energy distribution of each IMF. The train-induced bridge signals measured from a large-scale high-speed railway bridge are analyzed in this paper. The IMFs associated with the pseudo-frequencies caused by train or the resonant frequencies of bridge are distinguished. And, frequency variations are captured from the time–frequency energy distributions of envelope-normalized IMFs. The results show the proposed method can extract the frequency variations of low-energy IMFs effectively, which are hard to be observed from the time–frequency energy distribution of train-induced bridge response. The instantaneous frequency characteristics extracted from the train-induced bridge response could be the important support for investigating the VBI effect of train–bridge system.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-07-06T07:00:00Z
      DOI: 10.1142/S0219455420410023
      Issue No: Vol. 20, No. 13 (2020)
       
  • Adaptive Amplifier for a Test Vehicle Moving Over Bridges: Theoretical
           Study
    • Authors: Y. B. Yang, Z. L. Wang, K. Shi, H. Xu, J. P. Yang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      A vibration amplifier is first proposed for adding to a test vehicle to enhance its capability to detect frequencies of the bridge under scanning. The test vehicle adopted is of single-axle and modeled as a single degree-of-freedom (DOF) system, which was proved to be successful in previous studies. The amplifier is also modeled as a single-DOF system, and the bridge as a simple beam of the Bernoulli–Euler type. To unveil the mechanism involved, closed-form solutions were first derived for the dynamic responses of each component, together with the transmissibility from the vehicle to amplifier. Also presented is a conceptual design for the amplifier. The approximations adopted in the theory were verified to be acceptable by the finite element simulation without such approximations. Since road roughness can never be avoided in practice and the test vehicle has to be towed by a tractor in the field test, both road roughness and the tractor are included in the numerical studies. For the general case, when the amplifier is not tuned to the vehicle frequency, the bridge frequencies can better be identified from the amplifier than vehicle response, and the tractor is helpful in enhancing the overall performance of the amplifier. Besides, the amplifier can be adaptively adjusted to target and detect the bridge frequency of concern. For the special case when the amplifier is tuned to the vehicle frequency, the amplifier can improve the vehicle performance by serving as a tuned mass damper, as conventionally known. This case is of limited use since it does not allow us to target the bridge frequencies. Both bridge damping and vehicle speed are also assessed with their effects addressed.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-29T08:00:00Z
      DOI: 10.1142/S0219455421500425
       
  • An Efficient Dimension-Adaptive Numerical Integration Method for
           Stochastic Dynamic Analysis of Structures with Uncertain Parameters
    • Authors: Helu Yu, Bin Wang, Zongyu Gao, Yongle Li
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper presents a novel dimension-adaptive numerical integration method for dynamic analysis of structures with stochastic parameters subjected to deterministic excitations. First, an efficient dimension-adaptive algorithm is proposed to detect the importance of each random parameter involved in the structural model, based on which the quadrature nodes used for numerical integration can be collocated more reasonably. Then, the Gaussian quadrature formulas are used to evaluate the structural response statistics. To further improve the robustness and efficiency of the proposed method, the dimension-adaptive integration is only used to calculate the structural displacement response statistics. The velocity and acceleration response statistics are further evaluated using the finite difference formulas based on the concept of stochastic difference. Such a strategy is especially attractive when evaluating the response statistics of the derivative processes requires more quadrature nodes than that of the original process. Finally, two numerical examples encountered in civil engineering, including a shear frame with stochastic parameters subjected to a seismic ground motion and an Euler beam with unidimensional stochastic field of material properties (discretized via the Karhunen–Loève expansion) subjected to a moving load are studied to illustrate the performance of the proposed method. Via the numerical results, the accuracy and efficiency of the proposed method are verified.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-28T08:00:00Z
      DOI: 10.1142/S0219455421500358
       
  • Stability of Stainless Steel I-Section Beam-Columns at Elevated
           Temperatures
    • Authors: Merih Kucukler, Zhe Xing, Leroy Gardner
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      With the growing use of stainless steel in the construction and offshore industries, there is an increasing interest and need to study the performance of stainless structures at elevated temperatures. The behavior and design of stainless steel I-section beam-columns in fire is investigated in this paper, addressing a scarcity of previous research on this topic. Finite element (FE) models of stainless steel beam-columns, able to replicate their response at elevated temperatures, are created and validated; the validated models are then used to perform parametric studies to generate extensive benchmark structural performance data. The design rules set out in the European structural steel fire design standard EN 1993-1-2 are assessed and shown to provide rather inaccurate and often unsafe ultimate strength predictions for stainless steel I-section beam-columns in fire. New fire design rules for stainless steel beam-columns are put forward. It is shown that the new proposals are able to offer improved accuracy and design efficiency relative to the EN 1993-1-2 beam-column design rules. The reliability of the proposed design rules is also verified on the basis of the fire design reliability criteria set out by Kruppa [Eurocodes–Fire parts: Proposal for a methodology to check the accuracy of assessment methods, CEN TC 250, Horizontal Group Fire, Document no: 99/130 (1999)], thereby demonstrating the suitability of the proposed design rules for inclusion in the upcoming revised version of EN 1993-1-2.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-28T08:00:00Z
      DOI: 10.1142/S0219455421500371
       
  • Stochastic Extended Finite Element Implementation for Natural Frequency of
           Cracked Functionally Gradient and Bi-Material Structures
    • Authors: Ahmed Raza, Himanshu Pathak, Mohammad Talha
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this work, stochastic perturbation-based vibration characteristics of cracked bi-material and functionally graded material (FGM) domain with uncertain material properties are investigated using the extended finite element method. The level set function is implemented to track the geometrical discontinuities. The partition of unity-based extrinsic enrichment technique is employed to model the crack and material interface. The exponential law is used to model the graded material properties of FGM. The First-order perturbation technique (FOPT) is implemented to predict the standard deviation of natural frequency for the given uncertainties in the material properties. The numerical results are presented to show the effect of geometrical discontinuities and material randomness on vibration characteristics.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-28T08:00:00Z
      DOI: 10.1142/S0219455421500449
       
  • Breathing Crack Localization in Structures Based on Principal Component
           Analysis of Forced Vibration Responses
    • Authors: J. Prawin
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The identification of a breathing crack is a highly challenging inverse problem in structural health monitoring. A novel output-only damage diagnostic technique based on Principal Component Analysis (PCA) is proposed for breathing crack identification in structures excited by harmonic excitation. The proposed approach basically utilizes the residues obtained from PCA of the forced acceleration-time history responses of the structure for breathing crack identification. In this approach, the traditional single-tone, bitone and as well as multi-tone harmonic excitations are considered as input to the structure while exploring the residues of the responses for breathing crack identification. A new Damage Localization Index (DLI) based on the Fourier spectrum amplitudes of the nonlinear sensitive features (i.e. buried in residues), measured at varied locations spatially across the structure is proposed for breathing crack localization. The robustness and effectiveness of the proposed PCA-based breathing crack localization approach is verified through both numerical and experimental studies.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-24T08:00:00Z
      DOI: 10.1142/S0219455421500413
       
  • Periodic Response and Stability of a Maglev System with Delayed Feedback
           Control Under Aerodynamic Lift
    • Authors: Han Wu, Xiao-Hui Zeng, Ding-Gang Gao
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this research, the periodic response and stability of a nonlinear maglev system under the combined effects of steady and unsteady aerodynamic lifts is investigated, considering time delay in the feedback control loop. First, a nonlinear maglev system with a single levitation point that accounts for the nonlinearity of the electromagnetic force, time delay in the feedback control loop, and effect of aerodynamic lift is established. Then the periodic solutions of the maglev system with aerodynamic lift and time delays are obtained by an incremental harmonic balance analysis, in which the explicit time-delay action matrices used indicate that the effect of time delay on the response of the maglev system is periodic. The stability of the periodic solutions based on a finite difference continuous time approximation method and Floquet theory is studied, from which the critical time delay is obtained. Also, the relationship between the periodic vibration amplitude and the time delay is examined, along with the steady aerodynamic lift coefficient, and frequency of the unsteady aerodynamic lift, as well as the variation of critical delay with respect to the position feedback and velocity feedback with the control gain parameters. In addition, the stability boundary for the simultaneous time-delayed position and velocity feedback is obtained.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-23T08:00:00Z
      DOI: 10.1142/S0219455421500401
       
  • Thermal Postbuckling of Temperature-Dependent Functionally Graded
           Nanocomposite Annular Sector Plates Reinforced by Carbon Nanotubes
    • Authors: Raheb Gholami, Reza Ansari
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this study, the thermal buckling and postbuckling of functionally graded (FG) nanocomposite annular sector plates reinforced by carbon nanotubes (CNTs) are numerically analyzed. The effective material properties of FG nanocomposite are temperature-dependent (TD) and evaluated via the modified micromechanical method and rule of mixture. Based on the higher-order shear deformation theory (HSDT) and using the principle of virtual work and variational differential quadrature (VDQ) approach, the unified weak form of discretized nonlinear governing equilibrium equations is derived. Then, by using the linear part of equations and solving the derived eigenvalue problem, the critical temperature rise and associated mode shapes are obtained, which are used as the initial guess in solving the nonlinear thermal postbuckling problem. The pseudo-arc-length method and an iterative solver are employed to obtain the nonlinear thermal postbuckling equilibrium path of the FG nanocomposite annular sector plates. The influences of geometrical parameters, boundary conditions (BCs), CNT volume fraction, and CNT distribution pattern on the critical temperature rise and thermal postbuckling behavior of the FG nanocomposite annular sector plates are evaluated and discussed. Also, comparisons are made between the results considering the TD and temperature-independent (TID) properties. It is demonstrated that for higher values of sector angle, the effect of sector angle on the critical temperature rise and thermal postbuckling path is negligible. Moreover, by increasing the sector angle, the effect of BCs of straight edges vanishes, and the critical temperature rise and thermal postbuckling curves of for BCs of CSCS and SCSC approach those for CCCC and SSSS ones.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-22T08:00:00Z
      DOI: 10.1142/S0219455421500267
       
  • Nonlinear Blast Responses of Thin Shell Roof Over Long Span Structures
    • Authors: Jake Rennie, Sakdirat Kaewunruen, Charalampos Baniotopoulos
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper adopts both explicit and implicit finite element methods in a specialist package LS-DYNA to investigate the nonlinear, dynamic response of a long span shell roof structure when subjected to blast loading. Parametric studies have been carried out on blast loaded laminated glass plates with reference to experimental results obtained by European researchers. A case study that has been chosen is a light rail station in The Netherlands called The Erasmusline. Following the detonation of 15[math]kg TNT charge, explicit analysis showed breakage surrounding the rigid supports along the edge beam where modal vibrations are restrained. An implicit analysis has confirmed the resonances in global eigen-frequencies where most blast damage is localized around the roof canopy hence producing cracking and potential glass detachment from the panels without full structural demolition. This insight from this study will inform structural engineers about the potential modes of failure and preventative strategies to minimize further secondary losses of life or assets from a terrorist attack.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-21T08:00:00Z
      DOI: 10.1142/S0219455421500310
       
  • Damage Sensitive PCA-FRF Feature in Unsupervised Machine Learning for
           Damage Detection of Plate-Like Structures
    • Authors: Pei Yi Siow, Zhi Chao Ong, Shin Yee Khoo, Kok-Sing Lim
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Damage detection is important in maintaining the integrity and safety of structures. The vibration-based Structural Health Monitoring (SHM) methods have been explored and applied extensively by researchers due to its non-destructive manner. The damage sensitivity of features used can significantly ect the accuracy of the vibration-based damage identification methods. The Frequency Response Function (FRF) was used as a damage sensitive feature in several works due to its rich yet compact representation of dynamic properties of a structure. However, utilizing the full size of FRFs in damage assessment requires high processing and computational time. A novel reduction technique using Principal Component Analysis (PCA) and peak detection on raw FRFs is proposed to extract the main damage sensitive feature while maintaining the dynamic characteristics. A rectangular Perspex plate with ground supports, simulating an automobile, was used for damage assessment. The damage sensitivity of the extracted feature, i.e. PCA-FRF is then evaluated using unsupervised [math]-means clustering results. The proposed method is found to exaggerate the shift of damaged data from undamaged data and improve the repeatability of the PCA-FRF. The PCA-FRF feature is shown to have higher damage sensitivity compared to the raw FRFs, in which it yielded well-clustered results even for low damage conditions.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-19T08:00:00Z
      DOI: 10.1142/S0219455421500280
       
  • Forest Trees as Naturally Available Seismic Metamaterials: Low Frequency
           Rayleigh Wave with Extremely Wide Bandgaps
    • Authors: Muhammad, Tingkai Wu, C. W. Lim
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper presents a comprehensive study and it concludes that the resonance of forest trees with properly aligned conditions precisely working as naturally available locally resonant metamaterials that are equipped with wonderful capability of generating low frequency extremely wide bandgaps in the earthquake frequency range of interest. At the geophysical scale, the propagation of Rayleigh wave in the soft sedimentary soil basin experiences strong wave attenuation when the longitudinal resonant modes of trees are coupled with vertical component of the Rayleigh wave that mimic wave hybridization phenomena. A finite element-based numerical technique is adopted and we considered a total of 10 cases where spacing, height, thickness and mechanical properties of resonant trees are varied to study the Rayleigh wave propagation and attenuation mechanism. The trapping and/or mode conversion of Rayleigh wave by resonant trees is observed as dominant phenomena for wave attenuation. A time history analysis is conducted based on an actual earthquake record to validate the performance and efficiency of the bandgaps. The effects of ground stiffness, resonant tree mechanical and geometric properties on the bandgaps are also discussed. The study explores another peculiar characteristic of the forest trees that controls the propagation of seismic wave to protect a region from earthquake hazards. Our study may motivate the relevant organizations, authorities and global communities on the needs of forestation to reduce the earthquake catastrophe.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-16T08:00:00Z
      DOI: 10.1142/S0219455420430142
       
  • Dynamic Reliability Evaluation by First-Order Reliability Method
           Integrated with Stochastic Pseudo Excitation Method
    • Authors: Siyu Zhu, Tianyu Xiang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The stochastic pseudo excitation method (SPEM), which is based on the principle of pseudo excitation method (PEM), is introduced to represent the randomness of dynamic input in which the amplitude of excitation is adopted as a random variable. Based on the mathematic definition of power spectral density, a physical interpolation of the SPEM is discussed. Even if one random variable is involved in calculation, the effects of the uncertainties are required to be investigated. The SPEM offers a simple but quite effective way to solve the dynamic reliability problem. Through integrating the new algorithm into first-order reliability method (FORM), the dynamic reliability of uncertain structure subjected to random excitation is studied. A linear oscillator with three types of white noise is adopted to verify the SPEM for dynamic reliability of linear random vibration analysis. Also, the accuracy and efficiency of SPEM to handle the multi-degree-of-freedom structure is investigated in this paper.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-12T08:00:00Z
      DOI: 10.1142/S0219455421500243
       
  • An Efficient Non-Iterative Hybrid Method for Analyzing
           Train–Rail–Bridge Interaction Problems
    • Authors: Kang Shi, Xuhui He, Yunfeng Zou, Zhi Zheng
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The dynamic interaction problem for the train–rail–bridge (TRB) systems presents a computational challenge, especially for the analysis of large-size TRB coupling systems. To address this issue, an efficient non-iterative hybrid method (NHM) is proposed. With this method, the integrated TRB system is divided into three subsystems, i.e. the train subsystem, the rail subsystem, and the bridge subsystem. Based on the individual subsystems, a multi-step[math] technique is adopted in which a fine time step is used to analyze the high-frequency coupling vibration for the train and rail subsystems, and a coarse time step is adopted to calculate the low-frequency coupling vibration for the rail and bridge subsystem. Additionally, Zhais explicit integral method is used to predict the displacement of the wheelsets and the rail at the current time step before using the Newmark method. The proposed method incorporates the advantages of Zhai’s explicit method and the MS technique to avoid the iteration that may be required for the train–rail coupled analysis. The simulation fidelity and computational efficiency of the proposed method are demonstrated in the analysis of two examples of typical high-speed railway bridges. It was demonstrated that the proposed method can significantly enhance the computational efficiency, while maintaining a higher precision with a larger time step in comparison with other existing methods.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-12T08:00:00Z
      DOI: 10.1142/S0219455421500292
       
  • Parameter Influences on Rail Corrugation of Metro Tangential Track
    • Authors: Zhiqiang Wang, Zhenyu Lei
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Rail corrugation can reduce riding comfort by vibration and noise, and even cause running accident. In this paper, the vehicle–track coupled dynamic model was developed for a metro’s tangential track considering the wear in rail materials. The influences of different track structure parameters and vehicle speed on the generation and development of rail corrugation of the tangential track were analyzed using the developed model by the control variable method. The results show that for different parameters, the friction power in wheel–rail contact patch fluctuates with time, but the overall fluctuation range is relatively uniform. Meantime, an analysis of one-third octave curves of the friction power reveals that the characteristic frequencies of friction power are mainly concentrated in the middle and low frequency bands. At the dominant characteristic frequency, the longitudinal stiffness and damping of fasteners, and lateral and vertical damping of fasteners have less influence on rail corrugation, while the lateral and vertical stiffnesses of fasteners, spacing of fasteners, wheel–rail friction coefficient and vehicle speed have greater effect on rail corrugation. The changes in vertical stiffness and spacing of fasteners will cause the characteristic frequency of friction power to be offset, resulting in a shift from 80[math]Hz to 100[math]Hz, which will further lead to rail corrugation of the corresponding wavelength. Thus, it can be concluded that the vertical stiffness and spacing of fasteners have an important impact on the generation and development of rail corrugation at the specific frequency. Besides, the variations of the other variables bring little change to the characteristic frequencies of friction power as well as on rail corrugation. The mechanism of parameters unveiled here provides some guides for the parameter optimization problem on restraining the generation or development of rail corrugation on the tangential track.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-10T08:00:00Z
      DOI: 10.1142/S0219455421500346
       
  • Feasibility Study of Super-Long Span Bridges Considering Aerostatic
           Instability by a Two-Stage Geometric Nonlinear Analysis
    • Authors: Jiunn-Yin Tsay
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      To meet the need of constructing fixed cross strait links, super-long span bridge with a main span over 2 000[math]m is considered as a candidate for their ability to cross deep and wide straits. To this end, some super-long span bridges with proper cable and girder systems were previously proposed and studied. The major design considerations are aimed at adopting new cable material, increasing the entire rigidity of the bridge, stabilizing the dynamic characteristics, strengthening the deck sections, etc. In this paper, a brief review of main cable and girder system is first given of the concepts previously proposed for the design of super-long span bridges. Then some typical examples are studied, focused on various issues related to the design of super-long span bridges, including composite cable, the unstressed length and tension force of the main cable, the stiffness and mass effects of the deck on critical wind speed, and the critical wind speed of various cable systems. The most challenges in super-long span bridges are to solve aerostatic and aerodynamic instability at required design wind speed. In this connection, the wind-induced aerostatic instability of super-long span bridges is studied by a two-stage geometric nonlinear analysis for dead loads and wind loads. The developed program adopted herein for geometric nonlinear analysis was verified and confirmed before. The proposed methods (i.e. composite cable, slotted girder, increasing deck stiffness and mass, cable layout, etc.) obtained for all the examples are in agreement with this study, which indicates applicability of the design approaches presented.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-09T08:00:00Z
      DOI: 10.1142/S0219455421500334
       
  • Explicit Expressions for Buckling Analysis of Thin-Walled Beams Under
           Combined Loads with Laterally-Fixed Ends and Application to Stability
           Analysis of Saw Blades
    • Authors: Van Binh Phung, Ngoc Doan Tran, Viet Duc Nguyen, V. S. Prokopov, Hoang Minh Dang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper studies the critical issue of thin-walled beams with laterally fixed ends. The method for defining the formulae of twist moment for the beams subjected to combined loads was elucidated. Based on this, the governing differential equations of the beam were developed. The procedure for determining the critical state of the beam by the energy method was presented. With this procedure, the critical state of the beam concerned under three types of loadings such as axial force [math], bending moment [math] and distributed load [math] (or concentrated load [math]) was examined deliberately. The outcomes were presented in explicit closed-form, which can be illustrated in 2D and 3D graphs. Also, the analytical solution obtained was in agreement with the numerical one obtained by the commercial software NX Nastran. Furthermore, the analytical solutions were applied straightforwardly to explore the stability and design optimization of the tooth-blade for the new frame-type saw machine under an eccentric load. The result can also be promisingly used to study problems of thin-walled beams with laterally fixed ends subjected to other types of loads.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-07T08:00:00Z
      DOI: 10.1142/S0219455421500322
       
  • Experimental Study on Dynamic Amplification Factor of Simple-Supported
           Reinforced Concrete Beams Under Impact Loading Generated by an Impulse
           Hammer
    • Authors: Xue-Qian Wu, Bo Zhong, Yang Lv, Zhong-Xian Li, Nawawi Chouw
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The empirical formulas of dynamic amplification factor (DAF) specified in current bridge codes only consider the span or fundamental frequency of reinforced concrete (RC) girders in highway. Although investigations have been carried out on different bridges with considering the road roughness, vehicle–bridge interactions and travelling velocity, but most of them have been done numerically. In this study, experimental study of DAF was carried out on three simple-supported RC beams with different fundamental frequencies and different damage stages, i.e. without damage, cracked and yielded. Impulse hammer with four hammer heads of different hardness, i.e. black, red, green and brown, were used to generate impact forces with increasing duration. The impact tests were first carried out on the RC beams without any damage by impact hammer with different hammer heads. Then the RC beams were loaded by a concentrated static force at the mid-span to crack. Impact tests with different hammer heads were repeated on the cracked RC beams. Finally, the cracked beams were further loaded by a concentrated static force to yield of the longitudinal reinforcement. The impact tests were repeated on the yielded beams again. Load cells installed at the supports of the RC beams were used to measure the reaction force generated by the hammer, then DAF was calculated directly by dividing the peak reaction force with the peak impact force. Data obtained from tests, theoretical analysis and specification in codes were compared to examine the DAFs. Results show that the ratio of duration of the impact force and the period of the beams performed a significant effect on the DAFs of the beams.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-07T08:00:00Z
      DOI: 10.1142/S021945542150036X
       
  • Dynamic Stability of Simply Supported Beams With Multi-Harmonic Parametric
           Excitation
    • Authors: Chao Xu, Zhengzhong Wang, Baohui Li
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Determination of the regions of dynamic instability has been an important issue for elastic structures. Under the extreme climate, the external load acting on structures is becoming more and more complicated, which can induce dynamic instability of elastic structures. In this study, we explore the dynamic instability and response characteristics of simply supported beams under multi-harmonic parametric excitation. A numerical approach for determining the instability regions under multi-harmonic parametric excitation is developed here by examining the eigenvalues of characteristic exponents of the monodromy matrix based on the Floquet theorem, and the fourth-order Runge–Kutta method is used to calculate the dynamic responses. The accuracy of the method is verified by the comparison with classical approximate boundary formulas of dynamic instability regions. The numerical results reveal that Bolotin’s approximate formulas are only applicable to the low-order instability regions with a small value of the excitation parameter of simple parametric resonance. Multi-harmonic parametric excitation can significantly change the dynamic instability regions, it may cause parametric resonance on beams for longitudinal complex periodic loads. The influence of frequency and number of multiply harmonics on the parametrically excited vibration of the beam is explored. High-order harmonics with low-frequency have positive effects on the stable response characteristics for multi-harmonic parametric excitation. This paper provides a new perspective for the vibration suppression of parametric excitation. The developed procedure can be used for multi-degree-of-freedom (MDOF) systems under complex excitation (e.g. tsunami waves and strong winds).
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-05T08:00:00Z
      DOI: 10.1142/S0219455421500279
       
  • Preface: IJSSD Special Issue in Celebration of the 75th Anniversary of
           Professor J. N. Reddy
    • Authors: C. W. Lim
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.

      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-04T08:00:00Z
      DOI: 10.1142/S0219455420020046
       
  • Reconstructing the Mass Distribution Function of a Two-Span Beam With an
           Overhang via the Fundamental Mode
    • Authors: Li-Hua Zhang, Min He, Qi-Shen Wang, I. Elishakoff
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, we discuss the following inverse problem: how to reconstruct the mass distribution function of a two-span beam with an overhang via its polynomial fundamental mode and polynomial stiffness function. This leads to a basic equations group constituted by the coefficients of the mass distribution and the stiffness distribution function. To make the basic equations group match, one way is to divide it into two sub- equations, and solve them. We specify the method for solving this inverse problem, and research the existence and rationality of the positive solutions.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-04T08:00:00Z
      DOI: 10.1142/S0219455420430117
       
  • Aeolian Vibration Control of Power Transmission Line Using Stockbridge
           Type Dampers — A Review
    • Authors: Zhisong Wang, Hong-Nan Li, Gangbing Song
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Due to its inherent low damping, a power transmission line is prone to wind induced vibration. Vibration control is needed to suppress the aeolian vibration of the transmission-line to reduce the fatigue and to extend its service life. Though patented in 1928, more than 90 years ago, the Stockbridge damper or its variants are still commonly used for vibration suppression of conductors in modern day power transmission systems because of their advantages of simple structure, low cost, reliable operation and effective vibration suppression. This paper offers a comprehensive review of the development, modeling, analysis, and design of the Stockbridge-type dampers and their applications in Aeolian vibration control of power transmission lines. A Stock bridge-type damper is a dumbbell-shaped device that consists of a short messenger cable with two masses at the ends and a clamp at the middle to attach to a conductor. The friction among the strands in the messenger cable dissipations energy. A Stock bridge-type damper is essentially a tuned mass damper. For the modeling of a Stockbridge damper alone, the classis linear mechanics analysis, the nonlinear analysis, and finite element method (FEM) are reviewed. For the modeling of the combined damper and conductor system, this paper mainly reviews the Energy Balance Principle (EBP) that is relatively easy to use and can obtain the energy dissipated by the damper. Two important design issues, the damper parameter sensitivity analysis and damper location optimization, are discussed in this paper. This paper also briefly reviews the experimentation and fatigue related to a Stockbridge damper. In addition, this paper provides an outlook of future development, analysis, and application of Stockbridge-type dampers for conductor vibration control.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-04T08:00:00Z
      DOI: 10.1142/S0219455421300019
       
  • Seismic Control of a Self-Anchored Suspension Bridge Using Fluid Viscous
           Dampers
    • Authors: Dongming Feng, Jingquan Wang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      A self-anchored suspension bridge balances forces internally without external anchorage requirements, making it suitable for sites where anchorages would be difficult to construct. It often adopts either a full-floating or a semi-floating tower-girder connection system, which may result in large displacement responses along bridge longitudinal direction during earthquakes. This study investigated the efficacy of using the fluid viscous damper (FVD) for seismic control of a single-tower self-anchored suspension bridge. First, the energy dissipation behaviors of the FVD under sinusoidal excitations were studied. It revealed that besides the damper parameters (i.e. damping coefficient and velocity exponent) of an FVD itself, the energy dissipation capacity also relies on the characteristics of external excitations. Therefore, optimum damper parameters added to a structure should be determined on a case-by-case basis. Parametric study was then carried out on the prototype bridge, which indicated a tendency of decreasing the longitudinal deck/tower displacements and tower forces with increasing damping coefficient [math] and decreasing velocity exponent [math]. Compared with the linear FVD, the nonlinear FVD with a smaller velocity exponent can develop more rectangular force-displacement loops and thus achieve better energy dissipation performance. With selected optimum damper parameters (i.e. [math][math]kN[math]m[math][math]s[math] and [math]) for the two FVDs added between the deck and the tower, the longitudinal deck and tower displacements could be reduced by 54%, while the peak bending moment and shear force at the tower base could be reduced by 30% and 19%, respectively. It is concluded that the nonlinear FVD can provide a simple and efficient solution to reduce displacement responses of self-anchored suspension bridges while simultaneously reducing the bending moment and shear force in the tower.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-28T08:00:00Z
      DOI: 10.1142/S0219455421500255
       
  • Structural Behaviors of Integrally-Jointed Plywood Columns with Knot
           Defects
    • Authors: Zhuoyang Xin, Joseph Gattas
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Modern factory automation is enabling the economic production of timber building components with sophisticated integral mechanical joints. This paper investigates the governing compressive failure mechanisms of full-length integrally-jointed plywood box columns, and in particular seeks to understand the interaction between localized material knot defects, integral box joint capacity, and column strength. A new critical failure mechanism is identified based on experimental observations and numerical analysis of sections with varying sizes of knot defect, with column capacity governed by defect-induced transverse loading of integral box joints. Column capacity was shown to improve with localized joint strengthening in knot-defective regions, or with a defect-adaptive fabrication procedure that avoids identified defects during component plate machining. The new failure mechanism was also combined with prior understanding of plate buckling and pop-off failure mechanisms to propose an overall failure process for integrally-jointed plywood columns. Results from this paper can also inform development of other types of integrally-jointed thin-walled structures.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-26T08:00:00Z
      DOI: 10.1142/S021945542150022X
       
  • Equivalent Single Layer Models in Free Vibration Analysis of Laminated
           Multi-Layered Plates
    • Authors: Ireneusz Kreja, Agnieszka Sabik
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The performance of selected equivalent single-layer (ESL) models is evaluated within several classical benchmark tests for small amplitude free vibration analysis of multi-layered plates. The authors elaborated their own Finite Element software based on the first-order shear deformation (FOSD) theory with some modifications incorporated including a correction of the transverse shear stiffness and an application of zigzag type functions. Seven different ESL models were considered in the study; beside the classical FOSD model, there were three FOSD models with various transverse shear corrections and three ESL models enhanced by the application of zigzag functions and based on Reissner’s Mixed Variational Theorem.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-25T08:00:00Z
      DOI: 10.1142/S0219455420430087
       
  • Time Response Stress Analysis of Solid and Reinforced Thin-Walled
           Structures by Component-Wise Models
    • Authors: R. Azzara, E. Carrera, M. Filippi, A. Pagani
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper deals with the evaluation of time response analyses of typical aerospace metallic structures. Attention is focussed on detailed stress state distributions over time by using the Carrera Unified Formulation (CUF) for modeling thin-walled reinforced shell structures. In detail, the already established component-wise (CW) approach is extended to dynamic time response by mode superposition and Newmark direct integration scheme. CW is a CUF-based modeling technique which allows to model multi-component structures by using the same refined finite element for each structural component, e.g. stringers, panels, ribs. Component coupling is realized by imposing displacement continuity without the need of mathematical artifices in the CW approach, so the stress state is consistent in the entire structural domain. The numerical results discussed include thin-walled open and closed section beams, wing boxes and a benchmark wing subjected to gust loading. They show that the proposed modeling technique is effective. In particular, as CW provides reach modal bases, mode superposition can be significantly efficient, even in the case of complex stress states.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-25T08:00:00Z
      DOI: 10.1142/S0219455420430105
       
  • A New Damage Detection Method for Special-Shaped Steel Arch Bridges Based
           on Fractal Theory and the Model Updating Technique
    • Authors: X. X. Cheng, G. Wu, L. Zhang, F. B. Ma
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, an innovative two-level damage detection method applicable to real-world online structural health monitoring (SHM) systems is proposed for in-service large steel arch bridges. The method consists of Level 1 damage detection practice that includes strain data acquisition and damage location using the damage index based on the fractal theory, and Level 2 damage detection practice that includes acceleration sample acquisitions and dynamic model updating to quantify the damage. A numerical case study of the Yingzhou bridge based on various damage cases demonstrated the effectiveness of the proposed damage detection method. It is revealed that Level 1 damage detection is sufficiently robust against the standard measurement noise and normal temperature variations. The study results also indicated that the accuracy of Level 2 damage detection largely depends on whether the initial structure imperfections are taken into account, and whether the utilized model updating method is effective under model errors.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-25T08:00:00Z
      DOI: 10.1142/S0219455421500309
       
  • Undrained Seismic Stability of Dual Unsupported Circular Tunnels Subjected
           to Surcharge Loading
    • Authors: Rui Zhang, Gaoqiao Wu, Minghua Zhao, Ming Lei
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Undrained seismic stability of dual unsupported circular tunnels was investigated in this work using a self-developed code for adaptive finite element limit analysis. The so-called pseudo-static method was used to simulate the seismic effects during an earthquake. Accurate upper and lower bounds of seismic stability factor [math] were obtained by using an adaptive remeshing technique incorporated in the code. Comprehensive parametric studies of the problem variables, including the horizontal seismic coefficient [math], the relative spacing ratio [math]/[math], the relative depth ratio [math]/[math] and the strength ratio [math]/[math] were performed to provide dimensionless design tables for practical uses. In addition, visualized results from AFELA were summarized to reveal how the failure mechanism of dual tunnels would evolve with varying problems variables. Numerical results showed that both the stability and failure mechanism of dual tunnels can be much affected by seismic effects which should be carefully considered for a reasonable design in earthquake zones.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-25T08:00:00Z
      DOI: 10.1142/S0219455421710012
       
  • A Controllability-Based TO Approach for the Piezoelectric Actuator Design
           Considering Multimodal Vibration Control
    • Authors: Juliano F. Gonçalves, Emílio C. N. Silva, Daniel M. De Leon, Eduardo A. Perondi
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper addresses the design problem of piezoelectric actuators for multimodal active vibration control. The design process is carried out by a topology optimization procedure which aims at maximizing a control performance index written in terms of the controllability Gramian, which is a measure that describes the ability of the actuator to move the structure from an initial condition to a desired final state in a finite time interval. The main work contribution is that independent sets of design variables are associated with each modal controllability index, then the multi-objective problem can be split into independent single-objective problems. Thus, no weighting factors are required to be tuned to give each vibration mode a suitable relevance in the optimization problem. A material interpolation scheme based on the Solid Isotropic Material with Penalization (SIMP) and the Piezoelectric Material with Penalization (PEMAP) models is employed to consider the different sets of design variables and the sensitivity analysis is carried out analytically. Numerical examples are presented by considering the design and vibration control for a cantilever beam and a beam fixed at both ends to show the efficacy of the proposed formulation. The control performance of the optimized actuators is analyzed using a Linear-Quadratic Regulator (LQR) simulation.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-20T08:00:00Z
      DOI: 10.1142/S0219455420430099
       
  • Isogeometric Free Vibration Analysis of Curved Euler–Bernoulli Beams
           With Particular Emphasis on Accuracy Study
    • Authors: Zhuangjing Sun, Dongdong Wang, Xiwei Li
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      An isogeometric free vibration analysis is presented for curved Euler–Bernoulli beams, where the theoretical study of frequency accuracy is particularly emphasized. Firstly, the isogeometric formulation for general curved Euler–Bernoulli beams is elaborated, which fully takes the advantages of geometry exactness and basis function smoothness provided by isogeometric analysis. Subsequently, in order to enable an analytical frequency accuracy study, the general curved beam formulation is particularized to the circular arch problem with constant radius. Under this circumstance, explicit mass and stiffness matrices are derived for quadratic and cubic isogeometric formulations. Accordingly, the coupled stencil equations associated with the axial and deflectional displacements of circular arches are established. By further invoking the harmonic wave assumption, a frequency accuracy measure is rationally attained for isogeometric free analysis of curved Euler–Bernoulli beams, which theoretically reveals that the isogeometric curved beam formulation with [math]th degree basis functions is [math]th order accurate regarding the frequency computation. Numerical results well confirm the proposed theoretical convergence rates for both circular arches and general curved beams.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-20T08:00:00Z
      DOI: 10.1142/S0219455421500115
       
  • Failure Behavior of Double-Layer-Domes Subjected to Impact
    • Authors: E. Nazari, B. Shekastehband
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The dynamic failure behavior of double-layer-domes subjected to impact is studied numerically through the nonlinear finite element software LS-DYNA. The parameters considered in this work include the mass, velocity, and size of impactor, impact direction, roof weigh, geometric imperfection, rise-to-span ratio, and depth of dome. The dynamic time-history response and energy conversion of the structure are utilized to distinguish between the failure mechanism types. For the cases studied, it is found that failure of the structures falls into one of the three categories: (1) local shear failure, (2) partial progressive failure, and (3) full progressive failure. Non-failure case dominates the dome response when the kinetic energy of the impactor is small enough, and the structure can convert most of the kinetic energy into the strain energy, thereby absorbing the impact. Local shear failure occurs in a double-layer-dome when an impactor with very high kinetic energy strikes the dome. For an impactor striking with a mass of 5 to 300[math]ton and a velocity of 50 to 120[math]m/s, the double-layer-dome studied will suffer from partial progressive failure. Varying mass and velocity of the impactor in the range of 1 to 300[math]ton and 200 to 400[math]m/s, respectively, results in a tendency of the dome to exhibit local shear failure. Although impact direction does not cause a change in the failure mechanism type, there is a reduction in the severity of failure of the system as the impact angle increases. Roof weight has no dominant effect on the failure mechanism of the double-layer-dome. A small initial member imperfection with amplitude 0.001[math] does not change the progressive failure type. A large member imperfection of 0.01[math] triggers member buckling and leads to local shear failure of the dome. Except for some loading cases, the change in the rise to span ratio and depth of the dome does not seriously affect the failure mode.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-20T08:00:00Z
      DOI: 10.1142/S0219455421500152
       
  • Temperature-Dependent Vibration of Various Types of Sandwich Beams with
           Porous FGM Layers
    • Authors: Mohsen Rahmani, Sajjad Dehghanpour
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      By using a high order sandwich beams theory which is modified by considering the transverse flexibility of the core, free vibration characteristics of two models of sandwich beams are studied in this paper. In type-I, functionally graded layers coat a homogeneous core, and in type-II, an FG core is covered by homogeneous face sheets. To increase the accuracy of the model of the FGM properties, even and uneven porosity distributions are applied, and all materials are considered temperature-dependent. Nonlinear Lagrange strain and thermal stresses of the face sheets and in-plane strain of the core are considered. To obtain the governing equations of motion, Hamilton’s principle is used and a Galerkin method is used to solve them for simply supported and clamped boundary conditions. To verify the results of this study, they are compared with the results of literatures. Also, the effect of variation of temperature, some geometrical parameters and porosities on the frequency are studied.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-20T08:00:00Z
      DOI: 10.1142/S0219455421500164
       
  • Numerical and Experimental Analyses of Free and Forced Vibration of
           Thin-Walled Beams
    • Authors: Wassim Jrad, Foudil Mohri, Guillaume Robin, El Mostafa Daya
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The flexural–torsional vibration behavior of unrestrained and braced thin-walled beams is investigated by experimental and finite elements approaches. In the experimental part, tests in free and forced vibrations of thin walled beams with arbitrary sections are analyzed. By the help of an instrumental hammer test and a shaker machine, the natural frequencies and the response spectra of the beams are extracted in the range 1–400[math]Hz. Beam displacements are measured by some accelerometer transducers. The behavior is also investigated by the finite element method. In mesh process, 3D beams are adopted and an additional DOF is affected to the warping. The model is implemented in a home-made model. The numerical and experimental results are compared to numerical simulations of a commercial code. Test results and numerical simulations of the present model agree well. The model seems to be accurate especially in the presence of higher vibration and coupled modes.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-20T08:00:00Z
      DOI: 10.1142/S0219455421500188
       
  • Energy Similitude Correction Method for Free Vibration of Cylinders
    • Authors: Lilin Zhou
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Similitude theory has been applied to design scale models in many fields of engineering. As for free vibration of cylinders, the wall thickness is too thin to manufacture scale model, which leads to similitude distortion. The aim of this study is to correct the similitude distortion and establish the distorted similitude relationship for free vibration of cylinders. First, the complete and partial similitude relationships are deduced while the similitude distortion of wall thickness is discussed. Then, with analysis of similitude for energy, an equation with prediction of modal frequencies for prototype is established and the energy similitude correction method is proposed. Finally, through numerical examples, this method is verified and the influence of wall thickness variation on the accuracy of the proposed method is analyzed.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-20T08:00:00Z
      DOI: 10.1142/S0219455421500231
       
  • Influence of Material Stochasticity on Buckling Characteristics of
           Initially Imperfect Higher-Order Shear Deformable Gradient Plates
    • Authors: Mohammed Shakir, Mohammad Talha
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper demonstrates the influence of material stochasticity on buckling characteristics of higher-order shear deformable gradient plates with initial geometric imperfections. The gradient plates are assessed by smooth variation in the volume fraction of the constituents (i.e. ceramic and metal) as power-law distribution function in the thickness direction. The effective material properties are achieved by means of the Voigt model. Plate kinematic based on Reddy’s higher-order shear deformation theory (HSDT) associated with initial geometric imperfection in the transverse direction is employed. The governing differential equation is produced using a variational approach. The mean and standard deviation of the critical buckling load are evaluated using finite element method and a mean-centered first-order perturbation technique in order to highlight the variation in buckling response. Numerical results are compared both in deterministic and probabilistic frameworks along with convergence in support of efficacy and performance of the proposed model. Based on the results, it can be concluded that the combined influence of geometric imperfection and uncertain material properties prominently affect the buckling response of the gradient plates.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-11T08:00:00Z
      DOI: 10.1142/S0219455421500048
       
  • Magneto-Aeroelastic Internal Resonances of a Rotating Circular Plate Based
           on Gyroscopic Systems Decoupling
    • Authors: Wenqiang Li, Yuda Hu
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, a principal and 3:1 internal resonance of an edge-clamped conductive circular plate rotating in air-magnetic environment is investigated, where the electromagnetic force expressions and a simple empirical aerodynamic model are used in modelling. Based on the transverse displacement assumption with a combination of two degenerate linearized modes, the 2 degree of freedom (2-DOF) magneto-aeroelastic asymmetric nonlinear gyroscopic systems are derived by utilizing the Galerkin approach. The method of multiple scales and the solvable condition for the coefficient matrix of the gyroscopic systems is employed to decouple the 2-DOF nonlinear gyroscopic systems and achieve the nonlinear modulation equations of the steady state responses. The numerical results for the relationship between two eigenfrequencies verify the existence of 3:1 internal resonances of the circular plate rotating in air-magnetic field. In addition, the resonance amplitude varying with detuning parameters and excitation amplitudes are plotted under principal and 3:1 internal resonances, respectively. It is found that the system may lose stability generated by a Hopf bifurcation, which may finally evolve into chaotic state through period-doubling bifurcation of intermittent periodic responses.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-11T08:00:00Z
      DOI: 10.1142/S0219455421500103
       
  • An Intelligent Analysis Method for Human-Induced Vibration of Concrete
           Footbridges
    • Authors: Bo Fu, Xinxin Wei
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      It is essential to reliably predict the human-induced vibrations in serviceability design of footbridges to ensure the vibration levels to be within the acceptable comfort limits. The human-induced structural responses are dependent on the dynamic properties of structures and human-induced excitations. For concrete footbridges, the elastic modulus of concrete is a vital parameter for determining the dynamic structural properties. To this end, a two-stage machine learning (ML)-based method is first proposed for modeling the elastic modulus of concrete. At the first stage, the ensemble algorithm, i.e. the gradient boosting regression tree (GBRT), is used to predict the compressive strength by selecting eight parameters, including concrete ingredients and curing time, as the inputs. At the second stage, the elastic modulus of concrete is modeled by using the GBRT method with the compressive strength as the input. Pedestrian crowd-induced load is the most common and crucial design load for footbridges. To consider the inter- and intra-subject variability in walking parameters and induced forces among persons in a crowd, a load model is developed by associating a modified social force model with a walking force model. By integrating the two submodels of structure and excitation, an intelligent analysis method for human-induced vibration is finally developed. A concrete footbridge with typical box cross-section subjected to human-induced excitation is analysed to illustrate the application of the proposed method.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-11T08:00:00Z
      DOI: 10.1142/S0219455421500139
       
  • Moving Element Analysis of High-Speed Train-Slab Track System Considering
           Discrete Rail Pads
    • Authors: Tuo Lei, Jian Dai, Kok Keng Ang, Kun Li, Yi Liu
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper presents a study of the dynamic behavior of a coupled train-slab track system considering discrete rail pads. The slab track is modeled as a three-layer Timoshenko beam. The study is carried out using the moving element method (MEM). By introducing a convected coordinate system moving at the same speed as the vehicle, the governing equations of motion of the slab track are formulated in a moving frame-of-reference. By adopting Galerkin’s method, the element stiffness, mass and damping matrices of a truncated slab track in the moving coordinate system are derived. The vehicle is modeled as a multi-body with 10 degrees of freedom. The nonlinear Hertz contact model is used to account for the wheel–rail interaction. The Newmark integration method, in conjunction with a global Newton–Raphson iteration algorithm, is employed to solve the nonlinear dynamic equations of motion of the vehicle–track coupled system. The proposed MEM model of the system is validated through comparison with available results in the literature. Further study is then made to investigate the vehicle–track system accounting for track irregularities modeled as short harmonic wave forms. Results showed that irregularities with short wavelengths have a significant effect on wheel–rail contact force and rail acceleration, and the dynamic response of the track structure does not increase monotonously with the increase of the vehicle speed.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-11T08:00:00Z
      DOI: 10.1142/S0219455421500140
       
  • A Method to Estimate Dynamic Buckling Response of an Unstiffened Plate
           Elastically Restrained Along all Edges Under In-Plane Impact
    • Authors: Bin Yang, Kunkun Fu, Yan Li
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Unstiffened plates in structures are usually welded or fastened to supporting members, providing rotational restraint stiffness to the plate. Previous studies have shown that neglect of rotational restraint stiffness at the edges of a plate in a structure can introduce deviations in the analysis of dynamic elastic buckling. In this study, the in-plane impact-induced dynamic elastic buckling responses of isotropic imperfect unstiffened plates with four elastically restrained edges are analytically investigated, based on the large-deflection theory of thin plate. The evolution of the peak deflection predicted by the proposed analytical method is found to be consistent with the responses available from the literature. Then the method is further used to estimate the deformation map of an unstiffened plate with four elastically restrained edges, and the effects of rotational restraint stiffness, initial geometric imperfection and shock duration on the dynamic buckling response of the plate are examined. The results show that the critical dynamic buckling load and the maximum deflection response of the plates are significantly influenced by the rotational restraint stiffness as well as the first-order initial geometric imperfection, and thus cannot be neglected in the analysis of dynamic buckling.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-11T08:00:00Z
      DOI: 10.1142/S0219455421500218
       
  • A Comparison of Nonlinear Bending and Vibration of Hybrid Metal/CNTRC
           Laminated Beams with Positive and Negative Poisson’s Ratios
    • Authors: Yin Yu, Hui-Shen Shen
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Carbon nanotube reinforced composite (CNTRC) is one of the novel classes of advanced composite materials. This paper investigates the nonlinear bending and nonlinear vibration responses of hybrid laminated beams made of CNTRC layers bonded with metal layers on the top and bottom surfaces. We proposed a hybrid metal/CNTRC laminated beam for which out-of-plane Poisson’s ratio is negative. The effective material properties of CNTRC layers are graded in a piece-wise pattern across the thickness of the beam. The material properties of both CNTRC layer and metal layer are temperature dependent. The beams are rested on an elastic foundation and are located in thermal environments. Reddy’s higher-order beam model is used to establish the motion equations of the hybrid metal/CNTRC laminated beam. The motion equations include the von Kármán geometric nonlinearity, the thermal effects and the beam-foundation interaction. By employing a two-step perturbation approach, the bending and nonlinear vibration solutions are obtained. A comparison of nonlinear responses of hybrid metal/CNTRCl laminated beams with positive and negative Poisson’s ratios (NPRs) under different thermal environmental conditions is carried out and discussed in detail.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-07T08:00:00Z
      DOI: 10.1142/S0219455420430075
       
  • Dynamic Performance of the LMS Maglev Train–Track–Bridge System Under
           Uneven Settlement for Two Typical Bridges
    • Authors: Dangxiong Wang, Xiaozhen Li, Ziyan Wu
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      To investigate the dynamic performance of the low-to-medium-speed (LMS) maglev train and bridge system under uneven ground settlement, a refined vertical dynamic interaction model of the LMS maglev train–track–bridge system with uneven settlement is proposed. Firstly, the numerical model is verified based on the field test. Secondly, the dynamic performances of the system induced by uneven settlements are numerically analyzed. Furthermore, numerical studies are carried out to investigate the effect of various uneven settlement types, to compare the performances of the two typical bridges, and to assess the contribution of the F-rail in the presence of uneven settlement. The results show that uneven settlement has a significant enlargement effect on the dynamic responses of the car body and levitation module, but a very weak influence on the bridge. Both the patterns of uneven settlement and bridge types significantly affect the dynamic response of the maglev train to various levels. The numerical model excluding the track structure will overestimate the dynamic responses of the levitation module. It is suggested that the dynamic interaction model for the maglev train–track–bridge system be selected to simulate the influence of uneven settlement for better accuracy.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-07T08:00:00Z
      DOI: 10.1142/S0219455421500061
       
  • Analysis of Factors Affecting the Accuracy of Moving Force Identification
    • Authors: Zhen Chen, Lu Deng, Xuan Kong
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this study, the influence of the static component in the total force and the effective frequency bandwidth on the accuracy of force identification has been investigated. The acceleration and bending moment responses at different locations of a simply supported beam under different moving forces are numerically measured. The fast Fourier transformation is also introduced to analyze the frequency-domain component of the dynamic responses of the beam. Simulation results show that the dynamic characteristics of the vehicle, such as the frequency of dynamic vehicle load, have significant effect on the proportion of static component in the total vehicle load; the higher the proportion of static component in the total force, the higher the identification accuracy. In addition, the wider the effective frequency bandwidth, the higher the identification accuracy. The numerical results also show that both the proportion of static component in the total force and the effective frequency bandwidth vary with the type and location of measurement. To more accurately identify the moving force, it is necessary to analyze first the static component and frequency characteristics of the measured responses and to select appropriate type and location of measurement.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-03T08:00:00Z
      DOI: 10.1142/S021945542150019X
       
  • A Pyramidal Lattice Frame: Pathways to Inversion
    • Authors: Yue Guan, Lawrence N. Virgin
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper considers the load–deflection behavior of a pyramid-like, shallow lattice structure. It consists of four beams that join at a central apex and when subject to a lateral load, it exhibits a propensity to snap-through: a classical buckling phenomenon. Whether this structural inversion occurs, and the routes by which it happens, depends sensitively on geometry. Given the often sudden nature of the instability, the behavior is also examined within a dynamics context. The outcome of numerical simulations are favorably compared with experimental data extracted from the testing of three-dimensional (3D)-printed specimens. The key contributions of this paper are that despite the continuous nature of the physical system, its behavior (transient and equilibria) can be adequately described using a discrete model, and the paper also illustrates the utility of 3D-printing in an accessible research context.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-03T08:00:00Z
      DOI: 10.1142/S0219455421500206
       
  • Control of Magnetoelectric Load to Maintain Stable Compression Ratio for
           Free Piston Linear Engine Systems
    • Authors: Bo Yang, Chenheng Yuan, Jiahui Li
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The free piston linear engine system (FPLE) is considered as a promising powerplant, which has the advantages such as compact structure, short transfer path and variable compression ratio (CR) because the crank connecting rod is removed. However, the absence of crank-connecting rod inevitably produces uncertainty to the stable operation of the FPLE. A control system of the piston motion regulating for the FPLE is necessary. In this paper, the nonlinear dynamic model simulating the piston motion in a dual-piston FPLE is derived based on energy and force balance. The feasibility of the dynamic model is verified by experiment and simulation results. Based on instability mechanism analysis, a magnetoelectric load controller with motion stroke feedback is designed to maintain the piston position in a predefined CR by regulating the magnetoelectric force. The proposed magnetoelectric load controller is shown to have good control performance for the FPLE. The piston is always stabilized at the predefined position after a short adjustment time. The time of eliminating disturbance for the operation process is less than the start process. Furthermore, the increase in disturbance will result in the increase of time for adjustment.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-30T07:00:00Z
      DOI: 10.1142/S0219455421500176
       
  • Dynamic Force Loading Strategy for Effective Force Testing Considering
           Natural Velocity Feedback Compensation and Nonlinearity
    • Authors: Zhen Wang, Yong Ding, Aming Shi, Xizhan Ning, Bin Wu
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The effective force testing is a promising seismic testing method for evaluating the structural dynamic response to earthquakes for conciseness and efficiency. However, two challenging loading issues are associated with this method, i.e. the natural velocity feedback (NVF) and nonlinearities related to the interaction between the loading system and specimen, thereby hindering its development and extensive applications. To address these issues, this study proposes a dynamic force loading strategy using a hybrid algorithm with linear compensation for NVF and model reference adaptive control via the minimal control synthesis (MCS) method. Online identification of linear compensation gain in preliminary tests is conceived based on the gradient descent method. A series of numerical simulations on a nonlinear loading system model with linear/trilinear single/two degree(s)-of-freedom specimens are conducted using five loading strategies, including linear and nonlinear compensations and MCS method. Comparative studies show that the proposed method and nonlinear compensation strategy outperform the other three methods, and sometimes the proposed method performs best. In summary, the proposed method is promising because of its accuracy and robustness as well as its ease of implementation and cost-effectiveness.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-29T07:00:00Z
      DOI: 10.1142/S0219455421500073
       
  • Sensitivity Analysis of Composite Cellular Beams to Constitutive Material
           Models and Concrete Fracture
    • Authors: Felipe Piana Vendramell Ferreira, Carlos Humberto Martins, Silvana De Nardin
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Composite cellular beams are an advantageous solution that can be used to reduce floor height by solving service ducts problems. In the previous literature, there is little information on numerical modeling that considers sensitivity analysis in composite cellular beams, varying the constitutive models of steel and concrete materials. The concrete, when submitted by external loading, undergoes volume variations caused by inelastic deformations. The parameter that measures dilatancy is known as the dilation angle. This work aims to analyze the sensitivity of the computed response of composite cellular beams to the constitutive models of steel and concrete materials, and the parameters that constitute concrete damage plasticity (CDP). Geometrical nonlinear analyses are performed based on tests, considering solid elements for the composite slab and shear connectors, and shell elements for the cellular beam. It was concluded that the flexural behavior was not sensitive to dilation angles, unlike structures in which the resistance is governed by shear forces. For a dilation angle equal to [math], a better post-peak behavior was observed in the load-displacement relationship. It was found that by varying the viscosity parameter (or relaxation time), the load-displacement behavior relationship is not affected.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-29T07:00:00Z
      DOI: 10.1142/S0219455421500085
       
  • Vibration Analysis of Bidirectional Functionally Graded Timoshenko Beams
           Using Chebyshev Collocation Method
    • Authors: Wei-Ren Chen, Heng Chang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper studies the vibration behaviors of bidirectional functionally graded (BDFG) Timoshenko beams based on the Chebyshev collocation method. The material properties of the beam are assumed to vary simultaneously in the beam length and thickness directions. The Chebyshev differentiation matrices are used to reduce the ordinary differential equations into a set of algebraic equations to form the eigenvalue problem for free vibration analysis. To validate the accuracy of the proposed model, some calculated results are compared with those obtained by other investigators. Good agreement has been achieved. Then the effects of slenderness ratios, material distribution types, gradient indexes, and restraint types on the natural frequency of BDFG beams are examined. Through the parametric study, the influences of the various geometric and material parameters on the vibration characteristics of BDFG beams are evaluated.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-29T07:00:00Z
      DOI: 10.1142/S0219455421500097
       
  • Experimental and Numerical Analyses for Auto-Parametric Internal Resonance
           of a Framed Structure
    • Authors: Yuchun Li, Wei Liu, Chao Shen, Xiaojun Yang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The auto-parametric internal resonance experiment of a [math]-shaped frame is first conducted in this research. A non-contact electromagnetic vibration exciter is used to exert a periodic force on the vertical beam of the frame. The phenomena of internal resonance and non-internal resonance are observed and measured in this test. A common resonance of the vertical beam is excited by the external electromagnetic force, and the auto-parametric internal resonance of the horizontal beam is subsequently induced by the common resonance. The numerical method is also used to simulate the internal resonance and non-internal resonance. The stability boundaries of internal resonance and non-internal resonance are numerically and experimentally determined and compared. The numerical stability boundaries are in agreement with the experimental results. The results indicate that a small external excitation can excite a strong internal resonance response of a framed structure. The unstable domain of the internal resonance is much bigger than that of the non-internal resonance. The auto-parametric internal resonance is much more dangerous than the non-internal resonance. The risk of auto-parametric internal resonance should be emphasized and avoided in the designs of engineering structures.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-29T07:00:00Z
      DOI: 10.1142/S0219455421500127
       
  • Dynamic Stability and Response of Inclined Beams Under Moving Mass and
           Follower Force
    • Authors: D. S. Yang, C. M. Wang, J. D. Yau
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper is concerned with the dynamic stability and response of an inclined Euler–Bernoulli beam under a moving mass and a moving follower force. The extended Hamilton’s principle is used to derive the governing equation of motion and the boundary conditions for this general moving load/force problem. Considering a simply supported beam, one can solve the problem analytically by approximating the spatial part of the deflection with a Fourier sine series. Based on the formulation and method of solution, sample dynamic responses are determined for a beam that is inclined at 30[math] with respect to the horizontal. It is shown that the dynamic response of the beam under a moving mass is rather different from an equivalent moving follower force. Also investigated herein are the dynamic stability of inclined beams under moving load/follower force which are described by four key variables, viz. the speed of the moving mass/follower force, concentrated mass to the beam distributed mass, vibration frequency and the magnitude of the moving mass/follower force. The critical axial load and the critical follower force are different when they are located at different positions in the beam; except for the special case when they are at the end of the beam.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-23T07:00:00Z
      DOI: 10.1142/S021945542043004X
       
  • Free Vibrations of Functionally Graded Graphene-Reinforced Composite
           Blades with Varying Cross-Sections
    • Authors: Jie Chen, Pai Cui, Qiu-Sheng Li
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, free vibrations of functionally graded (FG) graphene-reinforced composite blades with varying cross-sections are investigated. Considering the cantilever boundary conditions, the dynamic model of a rotating blade is simplified as a varying cross-sections plate with pre-installed angle and pre-twisted angle. As a reinforcement, the graphene platelets (GPLs) are distributed either uniformly or gradiently on the plate along its thickness direction. The effective Young’s modulus is formulated by the modified Halpin–Tsai model. The rule of mixture is applied to calculate the effective Poisson’s ratio and mass density. The equations of motion are established by using the first-order shear deformation theory and von Karman geometric nonlinear theory. Based on the Rayleigh–Ritz method, the natural frequencies of the rotating FG blade reinforced with the GPLs are obtained. The accuracy of the present method is verified by comparing the obtained results with those of the finite element method and published literature. A comprehensive parametric study is conducted, with a particular focus on the effects of distribution pattern, weight fraction, and geometries size of the GPLs together with dimensional parameters of varying cross-sections blade on the dynamics of the FG blades reinforced with the GPLs.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-23T07:00:00Z
      DOI: 10.1142/S0219455420430063
       
  • Scale Dependent Critical External Pressure for Buckling of Spherical Shell
           Based on Nonlocal Strain Gradient Theory
    • Authors: Manjur Alam, Sudib Kumar Mishra, Tarun Kant
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Instabilities in nanosized, externally pressurized spherical shells are important for their applications in nano and biotechnology. Mechanics at such length scale is described by nonlocal and Strain Gradient (SG) field theories. However, analysis of shell buckling is involved and becomes even more complicated in presence of nonlocal and SG interactions. This paper demonstrates that such analysis can be largely simplified by a shallow segment representation of the shell by assuming short wave lengths for the incipient buckling modes. The governing equations are derived and linearized equations are solved to obtain a closed form solution for the critical external pressure causing buckling for a pressurized nonlocal shell. Nonlocal interactions are shown to reduce, whereas the SG interaction increases the critical pressure. The relative reduction/increase becomes more prominent for higher modes of buckling and for increasingly thinner shell. A constricting relationship between the two set of wave numbers expressing the buckling modes is also shown to be modified by the nonlocal and SG scale parameters. Consequent wave numbers increase/decrease, accompanied by decreasing/increasing number of wavelengths, thereby further justifying the shallow segment representation employed herein.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-23T07:00:00Z
      DOI: 10.1142/S0219455421500036
       
  • Experiments on Stability Performance of Thin-Walled, Open-Top Steel
           Storage Tanks Subjected to Local Support Settlement
    • Authors: Hamid Naseri, Hossein Showkati, Tadeh Zirakian, Sina Nasernia
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Local support settlement is a typical differential settlement which may take place under steel storage tanks and can adversely affect the stability performance of such thin-walled structures. Considering the practical applications of the thin-walled steel storage tanks in industry, proper treatment of this problem is essential to ensure the high structural performance of such members which albeit requires detailed investigations. On this basis, this study investigates the effects of the local support settlement on the buckling stability of two tanks without and with a top stiffening ring through the experimental and numerical approaches. The considered tanks are small-scale models with the height-to-radius and radius-to-thickness (slenderness) ratios of 1.0 and 834, respectively. Both experimental and numerical results show that the behavior of the tank under the local support settlement is nonlinear. Moreover, the effectiveness of the top stiffening ring in limiting the buckling deformation and improving the buckling performance of the tank is demonstrated in this study.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-23T07:00:00Z
      DOI: 10.1142/S021945542150005X
       
  • Influence of Non-Homogeneous Foundations On the Dynamic Responses of
           Railway Sleepers
    • Authors: Le-Hung Tran, Tien Hoang, Denis Duhamel, Gilles Foret, Samir Messad, Arnaud Loaëc
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In a railway track, the sleeper’s responses on a non-homogeneous foundation have been investigated by researchers focusing on the foundation behavior along the rails. However, the foundation can also vary along the sleeper length, particularly when the track is newly tamped. The foundation at the sleeper center is often weaker than those under the rails and this non-homogeneity directly affects the sleeper responses. This paper presents a new model to calculate the influence of such foundations on the dynamic responses of the railway sleepers. This model is developed by combining a finite element model for the sleepers and foundation and a model of periodically supported beams subjected to moving loads for the rails. In this paper, the foundation contains three parts with different mechanical behaviors. The sleeper’s responses can be calculated by transforming the finite-element dynamic stiffness matrix to the one considering the boundary conditions and the relation between the rail seat forces and rail displacements governed by the beam model. This method reduces all the degrees of freedom of the railway track to its one period which gives a substantial reduction in computational time. The numerical applications show that the more homogeneous (so-called consolidated) the foundation is, the larger the sleeper strain is at its center. This result shows the potential application of the sleeper responses to estimating the consolidation level of the foundation.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-19T07:00:00Z
      DOI: 10.1142/S0219455421500024
       
  • Bridge Surface Roughness Identified from the Displacement Influence Lines
           of the Contact Points by Two Connected Vehicles
    • Authors: Y. B. Yang, B. Q. Wang, Z. L. Wang, K. Shi, H. Xu, B. Zhang, Y. T. Wu
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this study, a new, effective procedure is proposed for identifying the surface roughness from the responses recorded of two connected test vehicles moving over the bridge. Central to this study is the proposal of a simple static correlation formula for relating the dynamic deflections of the two vehicles’s contact points on the bridge, via the displacement influence lines (DILs). With the aid of this relation, the roughness formula for estimating the bridge surface profile is derived using the responses of the leading and following vehicles. It does not require any prior knowledge of the dynamic properties of the bridge. The efficacy of the proposed procedure is validated for both the simple and three-span continuous beams by the finite element method (FEM). Also, a parametric study is conducted for various physical properties of the test vehicles. It is confirmed that the roughness profiles back-calculated from the proposed formula agree excellently with the assumed ones for both the simple and continuous beams. For use in practice, the two connected test vehicles should not be designed too heavy and not to move at too fast speeds, in order to reduce the impact on the bridge.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-13T07:00:00Z
      DOI: 10.1142/S0219455420430038
       
  • Gust Response Factor of a Transmission Tower Under Typhoon
    • Authors: Xing Fu, Wen-Long Du, Hong-Nan Li, Wen-Ping Xie, Kai Xiao, Xu Lei
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The gust response factors (GRFs) of transmission towers in current standards are reviewed for synoptic winds. The collapse of most transmission towers has occurred under the high-intensity wind (HIW) caused by events such as typhoons, hurricanes, and downbursts. Thus, this paper studies the GRF of a transmission tower under the typhoon. First, the definition of GRF and its extended form for the transmission towers are developed. Then the wind speed simulation of a typhoon event is introduced. Based on the structural health monitoring (SHM) system installed on tower #32, the measured GRFs under the super typhoon Mangkhut are calculated. Then the finite element model (FEM) of the transmission tower-line system is established to simulate the dynamic response to further calculate the GRFs, which agrees well with the field measurements. Both the field measurement and simulation results show that the GRFs under the typhoon are larger than those under the synoptic wind and that the recommended GRFs in the Chinese standard underestimate the peak responses. Finally, a parametric analysis is performed, which demonstrates that the turbulence intensity, wind speed, and power-law exponent all have great effects on the GRFs of transmission towers. In the HIW-prone areas, it is recommended that the characteristics of the HIW can be considered in improving the GRF values to guarantee the structural safety of transmission towers.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-10T07:00:00Z
      DOI: 10.1142/S0219455421500012
       
  • Nonlinear Dynamic Response of FG Graphene Platelets Reinforced Composite
           Beam with Edge Cracks in Thermal Environment
    • Authors: Zhicheng Yang, Meifung Tam, Yingyan Zhang, Sritawat Kitipornchai, Jiangen Lv, Jie Yang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper presents a numerical investigation on the nonlinear dynamic response of multilayer functionally graded graphene platelets reinforced composite (FG-GPLRC) beam with open edge cracks in thermal environment. It is assumed that graphene platelets (GPLs) in each GPLRC layer are uniformly distributed and randomly oriented with its concentration varying layer-wise along the thickness direction. The effective material properties of each GPLRC layer are predicted by Halpin-Tsai micromechanics-based model. Finite element method is employed to calculate the dynamic response of the cracked FG-GPLRC beam. It is found that the maximum dynamic deformation of the cracked FG-GPLRC beam under dynamic loading is quite sensitive to the crack location and grows with an increase in the crack depth ratio (CDR) and temperature rise. The influences of GPL distribution, concentration, geometry as well as the boundary conditions on the dynamic response characteristics of cracked FG-X-GPLRC beams are also investigated comprehensively.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-05T07:00:00Z
      DOI: 10.1142/S0219455420430051
       
  • Vibration of a Segmented Rod
    • Authors: C. Y. Wang, H. Zhang, C. M. Wang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper presents the governing equation of motion, boundary conditions and exact vibration frequencies of a segmented rod where the segments are connected by hinges with elastic rotational springs of constant stiffness. The mass of each segment is assumed to be evenly distributed along the length of the rod. Another discrete model called Hencky bar-chain model (short for HBM; which is equivalent to the finite difference model for discretizing continuous rod) assumes the rod mass to be lumped at the ends instead and a different set of boundary conditions are adopted clamped end. The vibration results of a clamped–clamped segment rod are compared with those of the HBM. It is shown that the HBM underestimates the vibration frequencies when compared to the segmented rod model for a finite number of segments while both models furnish vibration solutions that converge to the solutions of Euler beam for infinitely large number of segments.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-05T07:00:00Z
      DOI: 10.1142/S021945542071011X
       
  • Analytical Buckling Loads of Composite Rectangular Plates with Vertical
           and Rotational Springs Along the Edges
    • Authors: Joseph Tenenbaum, Moshe Eisenberger
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this research, a new analytical solution is used for finding the buckling loads of rectangular plates with vertically and rotationally restrained edges. The solution method in this study is based on the development of a static solution for a plate. The solution is obtained in series form, and the coefficients are solved to match the edge conditions. The solution fits all the combinations of possible boundary conditions, of the deflection, slope, shear force and bending moment along the edges of the plate. In the case of springs, the edge force and moment boundary conditions are modified to include these effects. Any number of edges, from one to four, with both types of stiffening springs can be solved. Using this new method, the exact buckling loads and modes are found. The results are verified with published data, and many new cases are presented for uni-axially and bi-axially loaded isotropic, orthotropic, and composite plates.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-01T07:00:00Z
      DOI: 10.1142/S0219455420430026
       
  • Dynamics of Precision Guided Projectile Launch: Solid–Solid
           Interaction
    • Authors: P. Verberne, S. A. Meguid
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Precision guided projectiles (PGPs) experience severe shock loads during launch emanating from the propellant gases inside the barrel and the surrounding air. The complex flow environment that exists within the confined space of the barrel and at muzzle exit is greatly influenced by the supersonic speed of the projectile, the compressibility of the air, and the rapid state transition of the projectile from the confined volume of the barrel to the surrounding free-space. In our earlier efforts (X. W. Yin, P. Verberne and S. A. Meguid, Multiphysics modelling of the coupled behaviour of precision-guided projectiles subjected to intense shock loads, Int. J. Mech. Mater. Des. 10 (2014) 439–450; P. Verberne and S. A. Meguid, The coupled behaviour of precision-guided projectiles subject to propellant induced shock loads using multiphysics analysis, in 8th Int. Conf. Mech. Mater. Des. (2019); P. Verberne and S. A. Meguid, Dynamics of precision guided projectile launch: Fluid-structure interaction, Acta Mech. (2020)) examined the fluid–solid interaction problem. In this paper, we expand our earlier effort by examining the underlying mechanisms associated with the solid–solid interaction between the projectile and the barrel walls that severely govern the survivability of the embedded electronic systems (EES). This was achieved by conducting comprehensive finite element (FE) simulations of the dynamics of the entire launch process of a projectile accounting for the intense combustion pressures of the propellant, the large accelerations experienced during the launch and the induced shock waves. Our FE simulations successfully capture the interaction of the projectile with the barrel. Our work reveals that frictional forces due to contact inside the barrel significantly affect the projectile’s acceleration response at muzzle exit. Immediately following muzzle exit, the rapid reduction of the frictional forces inside the barrel results in a rapid increase of the projectile acceleration followed by a rapid reduction due to the free expansion of the propellant gases and air drag, leading to large acceleration fluctuations.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-09-16T07:00:00Z
      DOI: 10.1142/S0219455420430014
       
 
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