Publisher: TULPAR Academic Publishing   (Total: 2 journals)   [Sort by number of followers]

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Challenge J. of Concrete Research Letters     Open Access   (Followers: 6)
Challenge J. of Structural Mechanics     Open Access   (Followers: 6)
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Challenge Journal of Structural Mechanics
Number of Followers: 6  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2149-8024
Published by TULPAR Academic Publishing Homepage  [2 journals]
  • Cover & Contents Vol.7 No.1

    • Authors: Journal Management CJSMEC
      PubDate: 2021-03-12
      Issue No: Vol. 7, No. 1 (2021)
  • Buckling analysis of natural fiber reinforced composites

    • Authors: Celal Çakıroğlu, Gebrail Bekdaş
      Abstract: In the recent years natural fiber reinforced composites are increasingly receiving attention from the researchers and engineers due to their mechanical properties comparable to the conventional synthetic fibers and due to their ease of preparation, low cost and density, eco-friendliness and bio-degradability. Natural fibers such as kenaf or flux are being considered as a viable replacement for glass, aramid or carbon. Extensive experimental studies have been carried out to determine the mechanical behavior of different natural fiber types such as the elastic modulus, tensile strength, flexural strength and the Poisson’s ratio. This paper presents a review of the various experimental studies in the field of fiber reinforced composites while summarizing the research outcome about the elastic properties of the major types of natural fiber reinforced composites. Furthermore, the performance of a kenaf reinforced composite plate is demonstrated using finite element analysis and results are compared to a glass fiber reinforced laminated composite plate.
      PubDate: 2021-01-02
      Issue No: Vol. 6, No. 4 (2021)
  • Strengthening and performance assessing historical cinema hall balcony
           according to new Turkish Earthquake Code

    • Authors: Memduh Karalar, Murat Çavuşli
      First page: 27
      Abstract: Strengthening historical buildings and evaluating their performances make great contributions to both the history of the country and the tourism of the country. In this study, performance analysis and evaluations of the historical cinema hall balcony, which was built in 1933 by a French company and served to Zonguldak province for a long time, are presented in detail. This cinema hall was frequently used by local people between 1933 and 1999 and hosted many Yeşilçam movies. Firstly, examinations were performed in the historical cinema hall and the areas (columns, beams and floors) that were damaged in time were identified. According to the obtained information, it was determined that there were significant damages in the carrier system of the building and there were visible cracks and damages in the columns of the cinema hall. It was also observed that explosions occurred in one of the main carrier columns of the balcony. After the core samples taken from the balcony were tested in the laboratory, the current status of the carrier elements and reinforcements were determined with the help of an x-ray rebar scanner. After all these processes, the structure was modeled as three dimensional (3D) using a special computer program and performance evaluations were performed regarding the current state of the structure. As a result of the performance evaluation, it was determined that the balcony of the historical cinema hall could not survive anymore and would collapse over time. It was concluded that there were great damages especially on the balcony columns and a reinforcement should be made on a total of 6 columns. Strengthening was made to 4 different main columns and a performance analysis was performed again in strengthened structure. After strengthening, it was understood that the columns of the balcony of the cinema hall could survive for a long time.
      PubDate: 2021-01-01
      DOI: 10.20528/cjsmec.2021.01.004
      Issue No: Vol. 6, No. 4 (2021)
  • Jaya algorithm based optimum design of reinforced concrete retaining walls
           under dynamic loads

    • Authors: Nur Eroğlu, Sena Aral, Sinan Melih Nigdeli, Gebrail Bekdaş
      Abstract: In this study, the optimum dimensioning of a reinforced concrete retaining wall that meets the safety conditions under static and dynamic loads in terms of cost has been performed using Jaya algorithm, which is one of the metaheuristic algorithms. In the optimization process, reinforced concrete design rules and ground stress, sliding and overturn tests have been determined as design constraints for the safe design of the retaining wall. While 5 cross-section dimensions of the retaining wall are defined as the design variable, the objective function is targeted as the total cost per unit length of the retaining wall. In the study, optimum results are also presented by examining the changes of the toe projection length of the retaining wall, which is one of the design variables, narrowing between 0.2-10 m. The design variables minimizing the objective function were found via Jaya algorithm that have single-phase. In addition to achieving optimum dimensioning results in terms of safety and cost with the optimization method used as a result of the reinforced concrete design made by applying the rules of the regulation on buildings to be constructed in earthquake zones, the change in cost in seismic and static conditions was examined.
      PubDate: 2020-12-31
      Issue No: Vol. 6, No. 4 (2020)
  • Cover & Contents Vol.6 No.4

    • Authors: Journal Management CJSMEC
      PubDate: 2020-12-20
      Issue No: Vol. 6, No. 4 (2020)
  • Determination of the exact mode frequencies of multi-storey structures by
           state-space method and a comparison with mode superposition method

    • Authors: Ahmad Yamin Rasa, Mehmet Hamit Özyazıcıoğlu
      First page: 1
      Abstract: A comparative research has been carried out for obtaining the time-consuming exact solution (state-space) and approximate solution (mode superposition) of transient and steady-state vibrations of linearly damped linear frame buildings. In the mode superposition method, the proportional damping matrix has been constructed by different approaches such as modal combination of mass and stiffness matrixes (Rayleigh) and disregarding the off-diagonal elements of the non-classical damping matrix, while in the state-space method the non-proportional damping matrix is constructed in exact situation. These observations are individually investigated, which the most suitable parameter to render the approximate results as close as possible to the exact results. Harmonic forces are applied on the different storeys of three and five storey frame buildings, and the responses are displayed in comparative tables and figures. The maximum responses are calculated by square root of sum of the squares (SRSS) method. A MATLAB code is generated and the equations of exact and approximate methods are solved.
      PubDate: 2020-12-21
      DOI: 10.20528/cjsmec.2021.01.001
      Issue No: Vol. 6, No. 4 (2020)
  • The effect of dome properties on design of the axial symmetric cylindrical

    • Authors: Aylin Ece Kayabekir
      First page: 11
      Abstract: The usage of computer software in civil engineering has expanded in last decades. Many general-purpose and special-purpose commercial programs perform a very important function, especially at the design stage. In this study, a computer program is introduced for the analysis and design of the axial symmetric cylindrical wall considering the dome effects. Analysis processes are carried out according to Flexibility theory with long wall assumption and during the reinforced concrete (RC) design of the wall, ACI 318-Building code requirements for structural concrete are considered. In numerical investigation, the effects of the dome properties (thickness and height) on the analysis and design of the wall are investigated by performing a totally 72 case analyzes. These cases include different support condition at bottom of the wall, wall heights, dome thicknesses and heights. According to analysis results, it is concluded that effects of dome thickness and heights on the wall on the wall are very limited.
      PubDate: 2020-12-26
      DOI: 10.20528/cjsmec.2021.01.002
      Issue No: Vol. 6, No. 4 (2020)
  • Evaluation of artificial neural network-based formulations for tuned mass

    • Authors: Melda Yucel, Sinan Melih Nigdeli, Gebrail Bekdaş
      First page: 17
      Abstract: Tuned mass dampers (TMDs) are used to damp vibration of mechanical systems. TMDs are also used on structures to reduce the effects of strong forces such as winds and earthquakes. For the efficiency of TMD, optimization of TMD parameters is needed. Several classical formulations were proposed, but metaheuristic methods are generally used to find the best result. In addition, the metaheuristic based optimum results are used in machine learning of artificial intelligence-based models like artificial neural networks (ANN). These ANN models are also used in development of tuning equation via curve fitting. The classical and ANN-based formulations were found according to frequency domain responses. In the present study, the classical and ANN-based formulations were evaluated by comparing on time-history responses of seismic structure. In comparison, near-fault ground motion records including directivity pulses are used. The ANN based methods have advantages by providing smaller stroke requirement and damping for TMDs.
      PubDate: 2020-12-22
      DOI: 10.20528/cjsmec.2021.01.003
      Issue No: Vol. 6, No. 4 (2020)
  • Effect of high temperature on the mechanical behavior of cement-bonded
           wood composite produced with wood waste

    • Authors: Mehmet Canbaz, İlkay Kara, İlker Bekir Topçu
      First page: 42
      Abstract: The increase in the population day by day and urbanization has led to a rapid increase in the construction sector. With the increase in demand in construction, the product types of building materials are increasing. It is seen that wastes are formed during and after the production of the materials used in the building. This highlights studies on waste management and recycling of waste.  After construction activities, wastes are recycled or converted to secondary products. One of these is wood waste, a traditional building material. In addition to the production of wood furniture, it is used in various areas from the beginning of construction to the end of the building. In this study, sawdust, which is the waste of a woodworking company, was used. Utilizing the advantages of wood, recyclable and sustainable cement bonded wood composite production practices have been explored. It is aimed to produce nature and environment friendly, ecological and economic and durable composite materials. In this research, it is aimed to determine the optimum ratio by using different ratios of sawdust-cement while keeping the water-cement ratio constant in production. The specimens taken from the production were exposed to high temperature after gaining strength. The strength results, unit weights and ultrasonic pulse velocity results of cement bonded wood composite samples exposed to high temperature were examined. Although cement bonded wood composites are exposed to high temperatures such as 400°C, it has been observed that strength is achieved. With this study, an alternative area was proposed for the evaluation of these wastes.
      PubDate: 2020-12-26
      DOI: 10.20528/cjsmec.2021.01.005
      Issue No: Vol. 6, No. 4 (2020)
  • Study on slope stability of frame prestressed anchor sheet pile wall with
           finite element strength reduction method

    • Authors: Amna Saeed Al-Banaa, Zhou Yong
      First page: 49
      Abstract: Slope stability analysis is performed in practical geotechnical engineering using the finite element method, which is an advanced method and is widely used by engineers. With the development of computer technology, it has become easy to study the slope's stability supported by frame prestressed anchor and sheet pile wall through the displacement-based finite element numerical analysis method, to calculate the safety factors. However, the expansion angle ψʹ is not widely covered. In this study, PLAXIS two-dimensional finite element method is using to establish the slope model supported by frame prestressed anchor and sheet pile wall, and the influence of expansion angle on slope deformation is studied. The results show that the expansion angle has a different effect on the convergence of the two-dimensional slope model. In the model slope, a prestressed frame anchor and sheet pile wall reinforce the slope. The failure mechanisms were unclear when ϕʹ= ψʹ (flow base). Besides, when the slope has high soil strength parameters (c' or φʹ), the expansion angle will affect the calculation results and convergence. In general, the expansion angle significantly influences the slope's stability and is not affected. Therefore, it was necessary to note the effect of the angle of expansion on stability.
      PubDate: 2020-12-30
      DOI: 10.20528/cjsmec.2021.01.006
      Issue No: Vol. 6, No. 4 (2020)
  • Seismic risk priorities of site and mid-rise RC buildings in Turkey

    • Authors: Ercan Işık, İbrahim Baran Karaşin, Alper Demirci, Aydın Büyüksaraç
      Pages: 191 - 203
      Abstract: Especially, the large-scale loss of life and property caused by the significant earthquakes in recent years has brought the importance of research and measures to be taken on this issue. Determining and analysing the ever-increasing building stock of the cities and detecting and managing all information related to buildings are important in terms of spatial planning and urban transformation. This study aims to determine tectonic characteristics calculating a and b values of Gutenberg- Richter magnitude-frequency relation which forms the basis of earthquake statistics for all cities in Turkey and the reinforced-concrete buildings which are primarily risky in terms of urban transformation. For this purpose, a total of 1620, 5-storey buildings from all provinces of Turkey were assessed. Twenty reinforced concrete buildings from each province were taken into consideration which has 5-stories. The first stage evaluation method specified in the principles regarding the identification of risky buildings issued in 2013 by the Republic of Turkey, Ministry of Environment and Urbanization was used in this study. The performance scores for 1620 buildings were calculated by using this method. A risk priority map was created for the provinces, taking into account for these buildings. The study aims to determine risk priorities of site and mid-rise reinforced-concrete buildings among the cities. The results obtained were interpreted and recommendations were made.
      PubDate: 2020-12-20
      DOI: 10.20528/cjsmec.2020.04.004
      Issue No: Vol. 6, No. 4 (2020)
  • Cover & Contents Vol.6 No.3

    • Authors: Journal Management CJSMEC
      PubDate: 2020-09-08
      Issue No: Vol. 6, No. 3 (2020)
  • Numerical investigation of sloshing with baffles having different

    • Authors: Abdullah Demir, Ali Ersin Dinçer
      First page: 176
      Abstract: Liquid tanks are indispensable members of civil engineering structures like liquid petroleum gas storage tanks and aerospace structures. Fluids can act unpredictably under earthquake excitation or dynamic loads. Loads applied to tank changes during motion and there can be deformations at the tank or even at the structure where the tank is placed. This is called sloshing and many researchers study the behavior of it. In this research, behavior of baffles having different elastic modulus is investigated by a fluid-structure interaction (FSI) method. The numerical method is a fully coupled FSI method proposed by the authors, recently. The method, which is verified by many problems, uses smoothed particle hydrodynamics (SPH) for fluid domain, finite element method (FEM) for structural domain and contact mechanics for coupling of these two domains. In analysis, a tank and a baffle having constant initial geometry are excited by harmonic motions. Elasticity of baffle is changed to investigate the effect on sloshing. Results show that tip displacement of baffle has linear relation with its elasticity for higher rigidities. In contrast, tip displacement of baffle has constant tip displacement for lower rigidities.
      PubDate: 2020-09-10
      DOI: 10.20528/cjsmec.2020.04.002
      Issue No: Vol. 6, No. 3 (2020)
  • The effect of slenderness on the lateral-torsional buckling and ultimate
           shear capacity of plate girders

    • Authors: Celal Cakiroglu, Kamrul Islam, Gebrail Bekdaş
      First page: 183
      Abstract: Lateral torsional buckling and shear buckling are two of the most significant structural responses that should be considered during the design process of plate girders. Particularly the importance of lateral torsional buckling was once again witnessed during the reconstruction process of a bridge in Edmonton, Alberta, Canada when the plate girders failed due to insufficient bracing. This current study aims to acquire a better understanding of the effect of geometric parameters such as the web slenderness, flange slenderness and span-to-depth ratio on the critical buckling moment and ultimate shear strength of plate girders. To achieve this goal the critical buckling moment and ultimate shear strength of a plate girder were parametrically studied for a large number of geometries using a load case from an experimental study. The results of this parametric study clarified the effects of web slenderness, flange slenderness and span-to-depth ratio on the structural performance of a plate girder. The visualization of the results was used to identify the ranges of these geometric parameters where the structural performance is most sensitive to changing them.
      PubDate: 2020-10-31
      DOI: 10.20528/cjsmec.2020.04.003
      Issue No: Vol. 6, No. 3 (2020)
  • Cover & Contents Vol.6 No.2

    • Authors: Journal Management CJSMEC
      PubDate: 2020-06-17
      Issue No: Vol. 6, No. 2 (2020)
  • A study on seismic isolation of building used LRB

    • Authors: Muhammet Yurdakul, Mehmet Burak Yıldız
      Pages: 52 - 60
      Abstract: Base isolation system with lead rubber bearing (LRB) is commonly used to prevent structure against to damage of earthquake. Design of LRB system is detailed in this study. The isolated building with LRB design according to Uniform Building Code (UBC-97) and fixed building were examined. The six-storey building with LRB and fixed building were modelled in SAP2000 with the same dynamic loads. The relative floor displacement and internal forces of the seismic isolated and fixed building are compared. In addition, transverse and longitudinal reinforcement of any axis of seismic isolated and fixed building are compared. Analyse results showed that effectiveness of using seismic isolation system on building. The weight of longitudinal and transverse reinforcement of isolated building is smaller than fixed building about 36%, 40% respectively.
      PubDate: 2020-06-17
      DOI: 10.20528/cjsmec.2020.02.001
      Issue No: Vol. 6, No. 2 (2020)
  • Use of trigonometric series functions in free vibration analysis of
           laminated composite beams

    • Authors: Muhittin Turan, Volkan Kahya
      Pages: 61 - 67
      Abstract: In this study, free vibration analysis of layered composite beams is performed by using an analytical method based on trigonometric series. Based on the first-order shear deformation beam theory, the governing equations are derived from the Lagrange’s equations. Appropriate trigonometric series functions are selected to satisfy the end conditions of the beam. Navier-type solution is used to obtain natural frequencies. Natural frequencies are calculated for different end conditions and lamina stacking. It was seen that the slenderness, E11/E22 and fiber angle have a significant effect on natural frequency. The results of the study are quite compatible with the literature.
      PubDate: 2020-06-17
      DOI: 10.20528/cjsmec.2020.02.002
      Issue No: Vol. 6, No. 2 (2020)
  • Comparison of short- and long-term ASR test methods on cementitious

    • Authors: Burak Sivrikaya, İlhami Demir, Özer Sevim
      Pages: 68 - 72
      Abstract: Concrete has a significant place in construction structures, is a material that can be easily damaged due to incorrect design, incorrect material selection. Concrete may be damaged by physical and chemical factors. One of these factors is the alkali-silica reaction (ASR). ASTM C1260, is a short-term test method, and ASTM C227, is a long-term test method, are used to measure effect of alkali-silica reaction. In this study, the effect of fly ash additive use with 0, 5, 10, 15, and 20 wt.% replacement of cement was investigated in short- and long-term ASR test methods. For this purpose, while samples prepared for ASTM C1260 were kept in NaOH solution 14-days, samples prepared for ASTM C227 were waited 360-days in normal water solution. As a result; mortar bars with 20% fly ash additive ratio were classified as harmless for ASR in both test methods.
      PubDate: 2020-06-17
      DOI: 10.20528/cjsmec.2020.02.003
      Issue No: Vol. 6, No. 2 (2020)
  • The effect of different fineness values of Afşin Elbistan fly ash on
           permeability in concrete

    • Authors: Demet Demir Şahin, Mustafa Çullu, Hasan Eker
      Pages: 73 - 83
      Abstract: Too much CO2 is released during cement production. In many researches, the use of natural or recycled compounds plays an important role in the cement composition. The use of these components contributes both to reducing the amount of waste and to protecting the environment in nature. It is possible to produce an environmentally friendly concrete, thanks to its being a fly ash thermal power plant waste and its use as mineral additive in terms of its composition. In this study, it is aimed to produce impermeable concretes with the use of C type fly ash as substitutes for cement in concrete composition in substitution rates of 10 %, 30 % and 50 %. In order to reduce the permeability of concrete in this direction, as a result of grinding the fly ash in the ball mill for 0, 10, 20, 30, 45 and 60 minutes, concrete samples were prepared with and without admixture (Reference). Capillarity test was performed to determine the permeability at the end of cure periods of 28 and 90 days on concrete samples. According to the results obtained at the end of 28 days, the best impermeability was achieved in the mixture with 50 % fly ash replacement and 60 minutes grinding time. In 90 days, the best impermeability was obtained in the mixture with 30 % fly ash replacement and 0 minutes of grinding time. As a result, it was seen that permeability decreased with increasing thinness and substitution rate of fly ash in concrete composition.
      PubDate: 2020-06-17
      DOI: 10.20528/cjsmec.2020.02.004
      Issue No: Vol. 6, No. 2 (2020)
  • The assessment of soil depth sensitivity to dynamic behavior of the
           Euler-Bernoulli beam under accelerated moving load

    • Authors: Amin Ghannadiasl, Hasan Rezaei Dolagh
      Pages: 84 - 90
      Abstract: Dynamic behavior is one of the most crucial characters in the railways structures. One of the items which leads to precise identification of the dynamic behavior of railways is the soil depth beneath them. In this paper, an Euler-Bernoulli beam on a finite depth foundation under accelerated moving load is presented. The dynamic equilibrium in the vertical direction is only regarded in accordance with the factor of finite beams. In this study, the dynamic equilibrium of the soil in the vertical direction and the sensitivity of soil depth are considered. The governing equations are simulated by using Fourier transform method. Eventually, by considering the sequences of shear waves, and different kinds of damping, displacement of the beam is obtained for the various acceleration, times and soil depth. As a result, it is shown that, higher acceleration is not dramatically effective on the beam displacement. Also, foundation inertia causes a significant reduction in critical velocity and can augment the beam response.
      PubDate: 2020-06-17
      DOI: 10.20528/cjsmec.2020.02.005
      Issue No: Vol. 6, No. 2 (2020)
  • Investigation of influence of concrete material models on cyclic inelastic
           response of a concrete filled composite plate shear wall

    • Authors: Erkan Polat
      Pages: 91 - 98
      Abstract: A previously benchmarked finite element model of a previously tested composite plate shear wall-concrete filled (C-PSW/CF) was used to investigate the influence of three concrete material models on in-plane cyclic inelastic wall response, using LS-Dyna. The concrete material models considered were the Winfrith, KCC and CSCM, all available in LS-Dyna. Wall moment hysteresis, using the three concrete material models, were obtained and compared. Individual contribution of the steel and concrete to total base moment was investigated for each wall with the three concrete material models. The numerical results obtained using the KCC and CSCM were compared against the benchmarked results obtained using the Winfrith concrete material model. Moment contribution of the steel web and the steel boundary on total base moment of the steel part of the wall and moment contribution of the concrete web and concrete boundary on total base moment of the concrete part of the wall were individually investigated. The wall models with the KCC and CSCM concrete models were observed to cannot capture wall pinching which was captured by the Winfrith concrete model. The wall strength was overpredicted by the CSCM concrete model and predicted reasonably by the KCC concrete model. Average axial stress distribution of the infill concrete was obtained to investigate wall neutral axis and the maximum attained concrete strength using the three concrete models. Concrete axial stress distribution showed some level of confinement for the concrete models considered.
      PubDate: 2020-06-17
      DOI: 10.20528/cjsmec.2020.02.006
      Issue No: Vol. 6, No. 2 (2020)
  • Design analysis of a steel industrial building with wide openings exposed
           to fire

    • Authors: Burak Kaan Cirpici
      First page: 99
      Abstract: In order to design a fire-resistant steel structure, the change in the physical and mechanical properties of the steel at high temperatures must be known. As the temperature of steel structural elements increases during fire, their strength decreases considerably. After a certain temperature, these strength drops reach critical levels. Therefore, collapses and various deformations (buckling, arching, etc.) occur. To prevent these collapses during the fire, various fire protection materials must be applied to the structural members such as column and beam. Columns are the most critical structural elements in a steel bearing system. While the possible collapse of the columns may cause the collapse of the whole structure, the beams alone may not cause the collapse of the structure, and the column-beam junctions directly affect the spread of fire. Since there will be many openings and gaps in industrial buildings, the spread and growth of a possible fire becomes very serious. Special fire protection measures are therefore required. In this study, the behavior of a steel industrial structure designed and designed under the influence of Standard Fire (ISO 834) was investigated, the distribution of the temperatures in the structural elements was determined, the required fire protection material was selected, and both protected and unprotected steel temperatures were determined. This design against fire is designed to provide fire resistance for 1 hour (60 min) for this structure. During this period, the type and optimum thickness of the protection material to be applied before reaching the critical temperature values for which the strength of the steel material would lose and would be damaged and compared with the temperatures that would occur in the structural elements without applying fire protection. According to the findings of the study, it was concluded that 25 mm drywall box protection material should be applied on the inner columns and 20 mm on the edge columns and 15 mm on the corner columns. In addition to this, it was concluded that spray beams (intumescent coating) of different thicknesses between 15-20 mm were applied to the beams depending on the location and the load to be affected and the type of joint. After these applied passive fire protection materials, the temperatures obtained in the structural elements reached to 500-550 as a result of 1-hour fire design. These temperatures are acceptable temperature values given the strength drop in critical temperature ranges for steel under the 1-hour fire condition.
      PubDate: 2020-07-04
      DOI: 10.20528/cjsmec.2020.03.001
      Issue No: Vol. 6, No. 2 (2020)
  • Moment-rotation behavior of semi-rigid web cleat connections

    • Authors: Merve Sağıroğlu, Mahyar Maali, Abdulkadir Cüneyt Aydın, Mahmut Kılıç
      First page: 110
      Abstract: The behavior of beam-column semi-rigid connection plays an important role in the response of a steel moment resisting, stiffness and rotation capacity framed structure, especially under static loading conditions. In this study, the moment-rotation characteristics of semi-rigid bolted connections using web cleat connections with IPE standard profile is discussed, based on the experimental investigation. The study revealed that the moment resistance of beam-column semi-rigid connection is improved by increasing the height of the beam to the height of web cleat joint (H), and the increasing thickness of web and flange in web cleat joints. The aim was to provide necessary data to improve the Eurocode 3 and efficiently use residue IPE standard profiles, rather than send them back to the consumption cycle. While the resistance moment increased with an increase in H from Hmin to Hmax.
      PubDate: 2020-07-04
      DOI: 10.20528/cjsmec.2020.03.002
      Issue No: Vol. 6, No. 2 (2020)
  • Blast-induced ground motion effect on dynamic response of a cylindrical
           vertical water tank with piled raft foundation

    • Authors: Kemal Hacıefendioğlu, Gökhan Demir, Ahmet Can Altunışık
      First page: 120
      Abstract: This paper studies to estimate the dynamic behavior of a demineralized water tank with a piled raft foundation system considering soil-pile-structure-fluid interaction to shock-ground motion. A three-dimensional finite element model of a coupled system is constituted in ANSYS software. Interaction between pile and soil is represented with the frictional contact element. The frictionless contact elements are utilized to model between the water and tank shell to allow for displacement of the free surface adjacent to the tank wall. Shell elements are used for the tank body and its vault. The dynamic analyses of the tank including soil-pile-structure-fluid interaction are presented by using shock response spectra. Ground shock acceleration time histories, generated by using a developed computer program based on Fortran programming language, produce shock response spectra. The effects of the different charge weights and distances from the charge center are examined in the analyses. Also, the effect of the water fill level in the tank and the number of piles is also investigated. The results of the research are presented with the directional displacements and equivalent stresses. It seen from the analyses that the dynamic responses of the tank increase with the charge weight, while decreasing with the charge center distance. Moreover, the water fill level and the number of piles extremely affect the displacement and stress values of the coupled interaction system.
      PubDate: 2020-07-04
      DOI: 10.20528/cjsmec.2020.03.003
      Issue No: Vol. 6, No. 2 (2020)
  • Numerical investigation on damage performance of a reinforced concrete
           structure subjected to machine loads

    • Authors: Memduh Karalar, Murat Çavuşli
      First page: 132
      Abstract: Investigation of carrying capacity performance of reinforced concrete (RC) structures is very important for structural engineering. In this study, it is aimed to examine the nonlinear carrying capacity performance of an RC laboratory structure by using three dimensional (3D) modelling approach. For this purpose, Zonguldak Bulent Ecevit University Laboratory Structure is selected and it is modeled as three dimensional by utilizing IDECAD static software. After modelling all beams, columns and floors according to 2018 Turkish earthquake code, concrete classes are determined for all bearing elements and specified concrete classes are defined for all elements of 3D model. Then, structure is analyzed for empty situation (Case 1) and structural performance of building is analyzed to this situation. In the past, a flat of this RC structure has been exposed to strong machine loads. For this reason, a machine which is fixed on the floor is placed in the 3D model and RC structure is analyzed considering nonstructural machine element loads (Case 2). According to analysis results, Case 1 is compared with Case 2 and it is clearly seen that nonstructural machine loads effect nonlinear carrying capacity performance of RC buildings.
      PubDate: 2020-07-04
      DOI: 10.20528/cjsmec.2020.03.004
      Issue No: Vol. 6, No. 2 (2020)
  • L-shaped reinforced concrete retaining wall design: cost and sizing

    • Authors: Aylin Ece Kayabekir, Zülal Akbay Arama, Gebrail Bekdaş, İlknur Dalyan
      First page: 140
      Abstract: In the context of this study, the design of L-shaped reinforced concrete retaining walls have been scrutinized parametrically depending on the simultaneous analysis of cost and sizing with the use of a recent optimization algorithm. The differences and restrictions of L-shaped reinforced concrete retaining wall design than classical T-shaped walls have been also discussed. The foundation width and the thickness of the wall required for a safe design has been also investigated according to the change of excavation depth, the type of soil dominating field and the external loading conditions. The observed results from optimization analyses shows that the variation of the shear strength angle is the most significant soil geotechnical parameter for supplying an envisaged safe design against sliding, overturning and adequate bearing capacity. Concurrently, the excavation depth is the most important factor that is forming the necessity of the construction of the retaining structure and optimal dimension evaluation. It is also proved that the wall foundation width is the most effected dimension of the retaining structures by the change of design parameters and the cost difference is directly influenced by the change of sizing. A cost-effective wall design can be performed with the use of proposed optimization analysis is capable in a shorter time than the traditional methods. Eventually, it has shown that such optimization methods may be useful to find the optimal design requirements for geotechnical engineering structures.
      PubDate: 2020-07-04
      DOI: 10.20528/cjsmec.2020.03.005
      Issue No: Vol. 6, No. 2 (2020)
  • Stress and displacement analysis of perforated circular plates

    • Authors: Mustafa Halûk Saraçoğlu, Fethullah Uslu, Uğur Albayrak
      First page: 150
      Abstract: Critical deflection and stress values of perforated circular plates under loads has an important role on the design criteria. For the perforated circular plates, the basic problem is determining how they have a perforation schema for the most suitable design. For this purpose, 10 different perforated circular plate models were presented and their static analysis was studied. All of the models have the same open area percentage but different number of holes. In this way, it was more convenient to compare the results. The circular plates were analyzed under their self-weight and uniformly distributed load with different nine thickness to diameter ratios obtained based on Classical Plate Theory. In addition, two set of analyses have been performed on the circular plates for fixed supported and simply supported boundary conditions. As an example, for the 6th model critical displacement and stress values under self-weight and under uniformly distributed load are investigated in detail. Designers of perforated circular plates can use the graphics presented in this study. The present study also purposes the shape optimization of thin circular perforated plates with round and staggered holes.
      PubDate: 2020-07-04
      DOI: 10.20528/cjsmec.2020.03.006
      Issue No: Vol. 6, No. 2 (2020)
  • Structural behavior of shear connectors embedded in different types of

    • Authors: Adil Hadi Wardi, Gökhan Tunç, Khalil Ibraheem
      First page: 160
      Abstract: Push-out tests are used to determine shear connectors’ properties where two small reinforced concrete walls are attached to the top and bottom flanges of an I-section through four shear studs located on both its flanges. In this study, the structural behavior of shear connectors was examined by testing a total of 36 push-out specimens. In these specimens, various test parameters were used. The types of shear connectors and their strengths, their connection types, and the strength of the concrete in which they were embedded were all investigated. Headed, L-shaped, and C-shaped studs were selected in this experimental study to represent different types of shear connectors. These shear connectors were assumed to be either ordinary or high strength steel-embedded in three different types of concrete: ordinary, high strength, and reactive powder concretes. In these tests, the shear connectors were connected through welding or epoxy bonding. The objective of this study was to investigate the structural behaviors of these different types of shear connectors by focusing on their shear force capacities and slip values. The test results indicate that the reactive powder concrete increased the mechanical properties of concrete as the concrete age increased. The specimens with C-shaped studs made of high-strength steel with welded studs embedded in normal weight, high strength and reactive powder concretes, generated the maximum shear resistance values.
      PubDate: 2020-07-05
      DOI: 10.20528/cjsmec.2020.04.001
      Issue No: Vol. 6, No. 2 (2020)
  • Comparison between fixed base and isolated base in seismic response of
           high-rise buildings: a case study

    • Authors: Anas M. Fares
      First page: 204
      Abstract: In this study, the influence of soil condition under the isolated and fixed bases is studied by using ETABS 16 software for the high-rise regular building. A regular building with 10 floors is modeled and the results are obtained for story displacements, story shear forces and spectral acceleration according to Uniform Building Code 97 (UBC-97) code. The time history analysis has been performed by using 1999 Izmit earthquake record. 3 types of soil which had different stiffnesses are considered in this study. The results show that the value of base shear increases when the soil stiffness decreases. It also noticed that the spectral acceleration is larger in soft soil condition than that of other soil conditions; and this confirms that the structural response spectrum is associated with the soil condition. In addition, when using base isolated building the drift of lower floors will be larger than that of using base isolated, but in the upper floors the drifts of fixed base building will be larger than that of the isolated base building. Finally, time history method in the seismic design will produce base shear less than that from equivalent static method, so calibration factor for design purpose shall be used.
      PubDate: 2020-07-05
      DOI: 10.20528/cjsmec.2020.04.005
      Issue No: Vol. 6, No. 2 (2020)
  • Structural performance of URM school buildings during the 2019 Albania

    • Authors: Marjo Hysenlliu, Huseyin Bilgin, Altin Bidaj, Marsed Leti
      First page: 215
      Abstract: This paper aims to study the seismic performance of school buildings, which have been built in accordance with template unreinforced masonry [URM] school projects in Albania. For this purpose, the most widely used two template designs which were damaged during the 2019 Durrës (Albania) Earthquakes, have been selected. Analytical models of each school were prepared following the experimental data on the quality of the masonry constitutive components of the selected school buildings. Geotechnical investigations were deployed to obtain the soil characteristics of the area where the schools’ foundation are located. Nonlinear static analyses have been performed to obtain the seismic capacity, the performance point and the damage level states. The performance-based method has been used to that purpose. The detailed examination of capacity curves and performance evaluation identified deficiencies and weak parts of the school building blocks. Results have shown that existing school buildings constructed pre-modern codes are far from satisfying the required performance criteria, suggesting that urgent response and necessary measure should be put into action.
      PubDate: 2020-07-06
      DOI: 10.20528/cjsmec.2020.04.006
      Issue No: Vol. 6, No. 2 (2020)
  • Cover & Contents Vol.6 No.1

    • Authors: Journal Management CJSMEC
      PubDate: 2020-03-25
      Issue No: Vol. 6, No. 1 (2020)
  • An investigation on determining optimum wall ratio–cost relationship of
           shear walled reinforced concrete buildings

    • Authors: İbrahim Hakkı Erkan, Talha Polat Doğan, Musa Hakan Arslan
      Pages: 1 - 9
      Abstract: Reinforced concrete walls are very efficient structural elements in terms of carrying the lateral loads that are expected to affect the structures during the service of the buildings. These elements, which are not used for economic reasons in buildings designed in areas with low seismic hazard, can actually provide a significant increase in performance with a very small increase in construction cost. In this study, a total of 9 building models have been created and the relationship between optimum reinforced concrete wall ratio and cost on these buildings has been investigated. The design and analysis of the models were carried out according to the criteria specified in TSC 2018. Three different structural systems specified in TSC 2018 were used in the designed models. These structural systems used; RC frame structures, RC wall-frame structures and RC wall structures. These structures were analyzed by Response Spectrum Method which is linear analysis method and base shear forces were obtained. Then, push-over analysis, which is a nonlinear analysis method, was applied to obtain the base shear forces that the structure can actually carry. After the analysis, the quantities of materials to be used for the construction of the structural systems of the models were calculated and current manufacturing prices and rough costs were calculated. In order to compare the obtained costs with the structural performances, nonlinear shear forces and linear shear forces ratios were calculated and the over strength factors were calculated for each model. In the light of the data obtained from the studies in the literature, when the over strength factors and cost values are examined together, it is concluded that the optimum design for the conditions specified in TSC 2018 will be provided with the RC wall ratio between 0.001 - 0.0016. It is concluded that lateral load carrying capacity of construction increases up to 650% by increasing the construction cost by 17% for the designed models.
      PubDate: 2020-03-25
      DOI: 10.20528/cjsmec.2020.01.001
      Issue No: Vol. 6, No. 1 (2020)
  • Evaluation of performance-based earthquake engineering in Yemen

    • Authors: Sulaiman Al-Safi, Ibrahim Abdullah Alameri, Rushdi A. M. Badhib, Mahmoud Kuleib
      Pages: 10 - 22
      Abstract: Building codes follow a common concept in designing buildings to achieve an acceptable seismic performance. The objective underlying the concept is to ensure that the buildings should be able to resist minor earthquake without damage, resist moderate earthquake with some non-structural damage, and resist major earthquakes without collapse, but some structural as well as non-structural damage. This study aims to evaluate the performance-based seismic to come up with necessary recommendations for both future practices, essential review, and restoration of existing structures in Yemen. To do this real case studies incorporated, and nonlinear pushover analysis is carried out. The analysis results presented and then assessed to find out the conformity with the required performance. The structural sections assumed at the beginning of the design, then the design repeated many times to achieve the selected performance criteria (the plastic hinge properties and the maximum displacement).
      PubDate: 2020-03-25
      DOI: 10.20528/cjsmec.2020.01.002
      Issue No: Vol. 6, No. 1 (2020)
  • Investigating the synergy between lean construction practices and post
           disaster management processes

    • Authors: Sevilay Demirkesen
      Pages: 23 - 30
      Abstract: Lean aims to maximize value while minimizing waste. Lean practices are likely to reduce the number potential hazards and errors. The use of Lean practices in construction is essential to experience less hazards. Benefitting from Lean practices has gained much attention in the last decade. Especially, the destroying effect of hazards and accidents is of utmost importance in terms of seeking for better strategies. Within this context, Lean practices offer a wide variety of advantages and provide means for achieving greater success in projects. This study investigates the use of Lean practices in post disaster management. Since post disaster management includes the activities to help community in rebuilding, Lean tools and techniques might be employed to better handle post disaster management processes. The study also scrutinizes the integration of Lean practices with the post disaster processes and encourages the community to compete against the destroying effect of disasters thanks to using Lean tools and techniques. The main contribution of this study is that it introduces Lean practices to be used in the post disaster management processes, which might potentially remove safety concerns in construction sites up to a great extent.
      PubDate: 2020-03-25
      DOI: 10.20528/cjsmec.2020.01.003
      Issue No: Vol. 6, No. 1 (2020)
  • Effect of configuration of shear walls at story plan to seismic behavior
           of high-rise reinforced concrete buildings

    • Authors: Mustafa Tolga Çöğürcü, Mehmet Uzun
      Pages: 31 - 40
      Abstract: In developing countries, the need for shelter, working area, shopping and entertainment centers is increasing due to the increasing population effect. In order to meet this need, it is necessary to turn to high-rise buildings. Significant damages have been observed as a result of insufficient horizontal displacement stiffness of high-rise buildings in major earthquakes in previous years. It is known that as the height of the structure increases, the displacement demand of the structure also increases. Since it is accepted that the structure will make inelastic deformation in the design of the structure, these displacements increase to very high levels as the number of stories increases. For this reason, damages can be much higher than expected. In order to limit the level of damage that may occur in high-rise buildings, the horizontal displacement of buildings is limited in many regulations in our age. This limitation is possible by increasing the rigidity of the structures against horizontal displacement. In recent years, the use of shear wall has increased due to the horizontal displacement limitation in the regulations. The use of shear walls in buildings limits the horizontal displacement. However, the choice of where the shear walls will be placed on the plan is very important. Failure to place the shear walls correctly may result in additional loads in the structure. It can also lead to torsional irregularity. In this study, a 10-storey reinforced concrete building model was created. Shear wall at the rate of 1% of the plan area of the building was used in the building. The shear walls are arranged in different geometric shapes and different layouts. The earthquake analysis of 5 different models were performed. Equivalent Earthquake Load, Mode Superposition and Time History Analysis methods were used for earthquake analysis. The results were compared and a proposal was made for the geometry and configuration of the shear wall.
      PubDate: 2020-03-25
      DOI: 10.20528/cjsmec.2020.01.004
      Issue No: Vol. 6, No. 1 (2020)
  • Model updating of a reduced-scaled masonry bridge by using response
           surface method

    • Authors: Emre Alpaslan, Zeki Karaca
      Pages: 41 - 51
      Abstract: Historical structures reflect the historical and cultural properties of countries and also contributes to the economy in terms of cultural tourism. Therefore, it is important to understand the structural behavior of these kinds of structures under dynamics loads such as earthquakes, etc. to protect and transfer them safely to future generations. For this reason, this study aims to investigate the dynamic behavior of a reduced-scale one-span masonry arch bridge constructed in laboratory conditions by performing experimental and numerical analysis. Operational Modal Analysis (OMA) Technique was performed under ambient vibrations for experimental study to determine modal parameters of the reduced-scaled bridge model. Sensitive three-axial accelerometers were located on critical points on the bridge span and signals originated by accelerometers were collected to quantify the vibratory response of the scale bridge model. The experimental natural frequencies, mode shapes and damping ratios resulting from these measurements were figured out by using Enhanced Frequency Domain Decomposition (EFDD) technique. ANSYS software was utilized to carry out 3D finite element (FE) modeling of the reduced-scale masonry bridge and determine the natural frequencies and mode shapes of the bridge numerically. Experimental results were compared with FE analysis results of the bridge. Significant differences appeared when comparing the results of the experimental and numerical with the initial conditions. Therefore, the finite element model is calibrated by using the response surface (RS) method according to the experimental results to minimize the uncertain finite element modeling parameters of the reduced-scale bridge model such as material properties.
      PubDate: 2020-03-25
      DOI: 10.20528/cjsmec.2020.01.005
      Issue No: Vol. 6, No. 1 (2020)
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
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