Pub Date : 2021-01-01DOI: 10.12989/SEM.2021.77.6.797
Abdelhak Zohra, Rabia Benferhat, Hassaine Daouadji Tahar, A. Tounsi
A new simple solution for critical buckling of FG sandwich plates under axial and biaxial loads is presented using new modified power-law formulations. Both even and uneven distributions of porosity are taken into account in this study. Material properties of the sandwich plate faces are assumed to be graded in the thickness direction according to a modified power-law distribution in terms of the volume fractions of the constituents. Equilibrium and stability equations of FG sandwich plate with various boundary conditions are derived using the higher-order shear deformation plate theory. The results reveal that the distribution shape of the porosity, the gradient index, loading type and functionally graded layers thickness have significant influence on the buckling response of functionally graded sandwich plates.
{"title":"Analysis on the buckling of imperfect functionally graded sandwich plates using new modified power-law formulations","authors":"Abdelhak Zohra, Rabia Benferhat, Hassaine Daouadji Tahar, A. Tounsi","doi":"10.12989/SEM.2021.77.6.797","DOIUrl":"https://doi.org/10.12989/SEM.2021.77.6.797","url":null,"abstract":"A new simple solution for critical buckling of FG sandwich plates under axial and biaxial loads is presented using new modified power-law formulations. Both even and uneven distributions of porosity are taken into account in this study. Material properties of the sandwich plate faces are assumed to be graded in the thickness direction according to a modified power-law distribution in terms of the volume fractions of the constituents. Equilibrium and stability equations of FG sandwich plate with various boundary conditions are derived using the higher-order shear deformation plate theory. The results reveal that the distribution shape of the porosity, the gradient index, loading type and functionally graded layers thickness have significant influence on the buckling response of functionally graded sandwich plates.","PeriodicalId":51181,"journal":{"name":"Structural Engineering and Mechanics","volume":"77 1","pages":"797-807"},"PeriodicalIF":2.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66124096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.12989/SEM.2021.78.1.087
X. Tu, Y. Wu, Zhengliang Li, Zhisong Wang
Long span cross-rope suspension structure is an innovative structural system evolved from typical Cross-Rope Suspension (CRS) guyed tower, a type of supporting system with short span suspension cable supporting overhead power transmission lines. In mountainous areas, the span length of suspension cable was designed to be extended to hundreds or over one thousand meters, which is applicable for crossing deep valleys. Vortex Induced Vibration (VIV) of overhead power transmission lines was considered to be one of the major factors of its fatigue and service life. In this paper, VIV and its controlling by Stockbridge damper for long span CRS was discussed. Firstly, energy balance method and finite element method for assessing VIV of CRS were presented. An approach of establishing FE model of long span CRS structure with dampers was introduced. The effect of Stockbridge damper for overall vibration of CRS was compared in both theoretical and numerical approaches. Results indicated that vibration characteristics of conductor in long span CRS compared with traditional tower-line system. Secondly, analysis on long span CRS including Stockbridge damper showed additional dampers installed were essential for controlling maximum dynamic bending stresses of conductors at both ends. Moreover, factors, including configuration and mass of Stockbridge damper, span length of suspension cable and conductor and number of spans of conductor, were assessed for further discussion on VIV controlling of long span CRS.
{"title":"Vortex induced vibration and its controlling of long span Cross-Rope Suspension transmission line with tension insulator","authors":"X. Tu, Y. Wu, Zhengliang Li, Zhisong Wang","doi":"10.12989/SEM.2021.78.1.087","DOIUrl":"https://doi.org/10.12989/SEM.2021.78.1.087","url":null,"abstract":"Long span cross-rope suspension structure is an innovative structural system evolved from typical Cross-Rope Suspension (CRS) guyed tower, a type of supporting system with short span suspension cable supporting overhead power transmission lines. In mountainous areas, the span length of suspension cable was designed to be extended to hundreds or over one thousand meters, which is applicable for crossing deep valleys. Vortex Induced Vibration (VIV) of overhead power transmission lines was considered to be one of the major factors of its fatigue and service life. In this paper, VIV and its controlling by Stockbridge damper for long span CRS was discussed. Firstly, energy balance method and finite element method for assessing VIV of CRS were presented. An approach of establishing FE model of long span CRS structure with dampers was introduced. The effect of Stockbridge damper for overall vibration of CRS was compared in both theoretical and numerical approaches. Results indicated that vibration characteristics of conductor in long span CRS compared with traditional tower-line system. Secondly, analysis on long span CRS including Stockbridge damper showed additional dampers installed were essential for controlling maximum dynamic bending stresses of conductors at both ends. Moreover, factors, including configuration and mass of Stockbridge damper, span length of suspension cable and conductor and number of spans of conductor, were assessed for further discussion on VIV controlling of long span CRS.","PeriodicalId":51181,"journal":{"name":"Structural Engineering and Mechanics","volume":"78 1","pages":"87"},"PeriodicalIF":2.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66124679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.12989/SEM.2021.78.3.231
Tao Zhang, Gong Yongzhi, F. Ding, Xue-mei Liu, Zhi-wu Yu
Pure bending loading conditions are not frequently occurred in practical engineering, but the flexural researches are important since it's the basis of mechanical property researches under complex loading. Hence, the objective of this paper is to investigate the flexural behavior of concrete-filled rectangular steel tube (CFRT) through combined experimental and numerical studies. Flexural tests were conducted to investigate the mechanical performance of CFRT under bending. The load vs. deflection curves during the loading process was analyzed in detail. All the specimens behaved in a very ductile manner. Besides, based on the experimental result, the composite action between the steel tube and core concrete was studies and examined. Furthermore, the feasibility and accuracy of the numerical method was verified by comparing the computed results with experimental observations. The full curves analysis on the moment vs. curvature curves was further conducted, where the development of the stress and strain redistribution in the steel tube and core concrete was clarified comprehensively. It should be noted that there existed bond slip between the core concrete and steel tube during the loading process. And then, an extensive parametric study, including the steel strength, concrete strength, steel ratio and aspect ratio, was performed. Finally, design formula to calculate the ultimate moment and flexural stiffness of CFRTs were presented. The predicted results showed satisfactory agreement with the experimental and FE results. Additionally, the difference between the experimental/FE and predicted results using the related design codes were illustrated.
{"title":"Experimental and numerical investigation on the behaviorof concrete-filled rectangular steel tubes under bending","authors":"Tao Zhang, Gong Yongzhi, F. Ding, Xue-mei Liu, Zhi-wu Yu","doi":"10.12989/SEM.2021.78.3.231","DOIUrl":"https://doi.org/10.12989/SEM.2021.78.3.231","url":null,"abstract":"Pure bending loading conditions are not frequently occurred in practical engineering, but the flexural researches are important since it's the basis of mechanical property researches under complex loading. Hence, the objective of this paper is to investigate the flexural behavior of concrete-filled rectangular steel tube (CFRT) through combined experimental and numerical studies. Flexural tests were conducted to investigate the mechanical performance of CFRT under bending. The load vs. deflection curves during the loading process was analyzed in detail. All the specimens behaved in a very ductile manner. Besides, based on the experimental result, the composite action between the steel tube and core concrete was studies and examined. Furthermore, the feasibility and accuracy of the numerical method was verified by comparing the computed results with experimental observations. The full curves analysis on the moment vs. curvature curves was further conducted, where the development of the stress and strain redistribution in the steel tube and core concrete was clarified comprehensively. It should be noted that there existed bond slip between the core concrete and steel tube during the loading process. And then, an extensive parametric study, including the steel strength, concrete strength, steel ratio and aspect ratio, was performed. Finally, design formula to calculate the ultimate moment and flexural stiffness of CFRTs were presented. The predicted results showed satisfactory agreement with the experimental and FE results. Additionally, the difference between the experimental/FE and predicted results using the related design codes were illustrated.","PeriodicalId":51181,"journal":{"name":"Structural Engineering and Mechanics","volume":"78 1","pages":"231"},"PeriodicalIF":2.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66125302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.12989/SEM.2021.78.3.255
Preeti Agarwal, P. Pal, P. Mehta
The analysis of simply supported single-cell skew-curved reinforced concrete (RC) box-girder bridges is carried out using a finite element based CsiBridge software. The behaviour of skew-curved box-girder bridges can not be anticipated simply by superimposing the individual effects of skewness and curvature, so it becomes important to examine the behaviour of such bridges considering the combined effects of skewness and curvature. A comprehensive parametric study is performed wherein the combined influence of the skew and curve angles is considered to determine the maximum bending moment, maximum shear force, maximum torsional moment and maximum vertical deflection of the bridge girders. The skew angle is varied from 0o to 60o at an interval of 10o, and the curve angle is varied from 0o to 60o at an interval of 12o. The scantly available literature on such bridges focuses mainly on the analysis of skew-curved bridges under dead and point loads. But, the effects of actual loadings may be different, thus, it is considered in the present study. It is found that the performance of these bridges having more curvature can be improved by introducing the skewness. Finally, several equations are deduced in the non-dimensional form for estimating the forces and deflection in the girders of simply supported skew-curved RC box-girder bridges, based upon the results of the straight one. The developed equations may be helpful to the designers in proportioning, analysing, and designing such bridges, as the correlation coefficient is about 0.99.
{"title":"Computation of design forces and deflection in skew-curved box-girder bridges","authors":"Preeti Agarwal, P. Pal, P. Mehta","doi":"10.12989/SEM.2021.78.3.255","DOIUrl":"https://doi.org/10.12989/SEM.2021.78.3.255","url":null,"abstract":"The analysis of simply supported single-cell skew-curved reinforced concrete (RC) box-girder bridges is carried out using a finite element based CsiBridge software. The behaviour of skew-curved box-girder bridges can not be anticipated simply by superimposing the individual effects of skewness and curvature, so it becomes important to examine the behaviour of such bridges considering the combined effects of skewness and curvature. A comprehensive parametric study is performed wherein the combined influence of the skew and curve angles is considered to determine the maximum bending moment, maximum shear force, maximum torsional moment and maximum vertical deflection of the bridge girders. The skew angle is varied from 0o to 60o at an interval of 10o, and the curve angle is varied from 0o to 60o at an interval of 12o. The scantly available literature on such bridges focuses mainly on the analysis of skew-curved bridges under dead and point loads. But, the effects of actual loadings may be different, thus, it is considered in the present study. It is found that the performance of these bridges having more curvature can be improved by introducing the skewness. Finally, several equations are deduced in the non-dimensional form for estimating the forces and deflection in the girders of simply supported skew-curved RC box-girder bridges, based upon the results of the straight one. The developed equations may be helpful to the designers in proportioning, analysing, and designing such bridges, as the correlation coefficient is about 0.99.","PeriodicalId":51181,"journal":{"name":"Structural Engineering and Mechanics","volume":"78 1","pages":"255"},"PeriodicalIF":2.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66125392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.12989/SEM.2021.78.4.425
J. Sadeghi, E. Haghighi, M. Esmaeili
Under foundation shock mats have been used in the current practice in order to reduce/damp vibrations received by buildings through the surrounding environment. Although some investigations have been made on under foundation shock mats performance, their effectiveness in the reduction of railway induced-vibrations has not been fully studied, particularly with the consideration of underneath soil media. In this regard, this research is aimed at investigating performance of shock mat used beneath building foundation for reduction of railway induced-vibrations, taking into account soil-structure interaction. For this purpose, a 2D finite/infinite element model of a building and its surrounding soil media was developed. It includes an elastic soil media, a railway embankment, a shock mat, and the building. The model results were validated using an analytical solution reported in the literature. The performance of shock mats was examined by an extensive parametric analysis on the soil type, bedding modulus of shock mat and dominant excitation frequency. The results obtained indicated that although the shock mat can substantially reduce the building vibrations, its performance is significantly influenced by its underneath soil media. The softer the soil, the lower the shock mat efficiency. Also, as the train excitation frequency increases, a better performance of shock-mats is observed. A simplified model/method was developed for prediction of shock mat effectiveness in reduction of railway-induced vibrations, making use of the results obtained.
{"title":"Performance of under foundation shock mat in reduction of railway-induced vibrations","authors":"J. Sadeghi, E. Haghighi, M. Esmaeili","doi":"10.12989/SEM.2021.78.4.425","DOIUrl":"https://doi.org/10.12989/SEM.2021.78.4.425","url":null,"abstract":"Under foundation shock mats have been used in the current practice in order to reduce/damp vibrations received by buildings through the surrounding environment. Although some investigations have been made on under foundation shock mats performance, their effectiveness in the reduction of railway induced-vibrations has not been fully studied, particularly with the consideration of underneath soil media. In this regard, this research is aimed at investigating performance of shock mat used beneath building foundation for reduction of railway induced-vibrations, taking into account soil-structure interaction. For this purpose, a 2D finite/infinite element model of a building and its surrounding soil media was developed. It includes an elastic soil media, a railway embankment, a shock mat, and the building. The model results were validated using an analytical solution reported in the literature. The performance of shock mats was examined by an extensive parametric analysis on the soil type, bedding modulus of shock mat and dominant excitation frequency. The results obtained indicated that although the shock mat can substantially reduce the building vibrations, its performance is significantly influenced by its underneath soil media. The softer the soil, the lower the shock mat efficiency. Also, as the train excitation frequency increases, a better performance of shock-mats is observed. A simplified model/method was developed for prediction of shock mat effectiveness in reduction of railway-induced vibrations, making use of the results obtained.","PeriodicalId":51181,"journal":{"name":"Structural Engineering and Mechanics","volume":"78 1","pages":"425"},"PeriodicalIF":2.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66125881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.12989/SEM.2021.78.6.665
I. Katili
This study proposes DSTK, a new incompatible triangular element formulated from a combination of discrete shear constraints, independent transverse shear strains and a free formulation approach. DSTK takes into account transverse shear effects and is valid for thin and thick plates. Furthermore, this element has 3 nodes and 3 DOFs per node (transverse displacement w and rotations Bx and By). The couple between lower order and higher order bending energy is assumed to be zero to fulfil the constant bending patch test. Unifying and integrating kinematic relationship, constitutive law, and equilibrium equations contribute to the independent transverse shear strain expression, which comprises merely the second derivatives of the rotations. The study performs validation based on individual element tests, patch tests, and convergence tests. This study shows that the DSTK element yields good results of various classical benchmark tests for thin to thick plates.
{"title":"An improved incompatible DSQ element using free formulation approach","authors":"I. Katili","doi":"10.12989/SEM.2021.78.6.665","DOIUrl":"https://doi.org/10.12989/SEM.2021.78.6.665","url":null,"abstract":"This study proposes DSTK, a new incompatible triangular element formulated from a combination of discrete shear constraints, independent transverse shear strains and a free formulation approach. DSTK takes into account transverse shear effects and is valid for thin and thick plates. Furthermore, this element has 3 nodes and 3 DOFs per node (transverse displacement w and rotations Bx and By). The couple between lower order and higher order bending energy is assumed to be zero to fulfil the constant bending patch test. Unifying and integrating kinematic relationship, constitutive law, and equilibrium equations contribute to the independent transverse shear strain expression, which comprises merely the second derivatives of the rotations. The study performs validation based on individual element tests, patch tests, and convergence tests. This study shows that the DSTK element yields good results of various classical benchmark tests for thin to thick plates.","PeriodicalId":51181,"journal":{"name":"Structural Engineering and Mechanics","volume":"78 1","pages":"665-679"},"PeriodicalIF":2.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66126208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.12989/SEM.2021.79.1.009
Emre Alpaslan, Z. Karaca
Response surface (RS) methods, a combination of mathematical and statistical techniques, have been widely used in design optimization, response prediction, and model validation in structural engineering systems. However, its usage in structural damage identification, especially for historic structures has not been quite common. For this purpose, this study attempts to investigate damage detection in a masonry arch bridge. Within the scope of this, a reduced-scale model of a one span historical masonry arch bridge was built in a laboratory environment. To determine the modal parameters of the reduced-scaled bridge model, operational modal analysis (OMA) was performed under ambient vibrations. Signals originated by sensitive accelerometers were collected to quantify the vibratory response of the reduced-scaled model bridge. The experimental natural frequencies, mode shapes, and damping ratios resulting from these measurements were figured out by using the Enhanced Frequency Domain Decomposition (EFDD) technique. The three-dimensional model of the reduced-scale bridge was created in the ANSYS finite element (FE) software program to expose the analytical dynamic characteristics of the bridge model. The results obtained in the experimental application were compared with those of the finite-element analysis of the bridge model. The calibration of the numeric model was utilized depending on the experimental modal analysis results of the reduced-scale bridge by using the RS method. Design of experiments was constructed by using central composite design, and the RS models were generated by performing the genetic aggregation approach. The optimum results between the experimental and numerical analyses were found by using the RS optimization. Then, regional damages created on the scaled model and the changes of dynamic properties of the damaged case were evaluated. The damage location was approximately identified by using the RS method in the calibrated finite-element model. The results demonstrated that the RS-based FE updating approach is an effective way for damage detection and localization in masonry type structures.
响应面方法是一种数学与统计相结合的方法，已广泛应用于结构工程系统的设计优化、响应预测和模型验证等方面。然而，它在结构损伤识别，特别是历史建筑损伤识别中的应用并不普遍。为此，本研究试图对砖石拱桥的损伤检测进行研究。在此范围内，在实验室环境下建立了一座单跨历史砌体拱桥的缩小模型。为了确定桥梁模型的模态参数，进行了环境振动下的运行模态分析(OMA)。通过采集敏感加速度计产生的信号，量化了模型桥梁的振动响应。利用增强频域分解(Enhanced Frequency Domain Decomposition, EFDD)技术计算得到实验固有频率、模态振型和阻尼比。在ANSYS有限元软件中建立缩比桥梁的三维模型，揭示桥梁模型的解析动力特性。将试验应用结果与桥梁模型有限元分析结果进行了比较。利用RS法对该桥梁进行了减尺试验模态分析，对数值模型进行了标定。采用中心组合设计构建试验设计，采用遗传聚集法生成RS模型。利用RS优化方法，在实验和数值分析中找到了最优的结果。在此基础上，对模型所产生的区域损伤和损伤体动力特性的变化进行了评价。在标定后的有限元模型中，采用RS法对损伤位置进行了近似识别。结果表明，基于rs的有限元更新方法是砌体结构损伤检测与定位的有效方法。
{"title":"Response surface-based model updating to detect damage on reduced-scale masonry arch bridge","authors":"Emre Alpaslan, Z. Karaca","doi":"10.12989/SEM.2021.79.1.009","DOIUrl":"https://doi.org/10.12989/SEM.2021.79.1.009","url":null,"abstract":"Response surface (RS) methods, a combination of mathematical and statistical techniques, have been widely used in design optimization, response prediction, and model validation in structural engineering systems. However, its usage in structural damage identification, especially for historic structures has not been quite common. For this purpose, this study attempts to investigate damage detection in a masonry arch bridge. Within the scope of this, a reduced-scale model of a one span historical masonry arch bridge was built in a laboratory environment. To determine the modal parameters of the reduced-scaled bridge model, operational modal analysis (OMA) was performed under ambient vibrations. Signals originated by sensitive accelerometers were collected to quantify the vibratory response of the reduced-scaled model bridge. The experimental natural frequencies, mode shapes, and damping ratios resulting from these measurements were figured out by using the Enhanced Frequency Domain Decomposition (EFDD) technique. The three-dimensional model of the reduced-scale bridge was created in the ANSYS finite element (FE) software program to expose the analytical dynamic characteristics of the bridge model. The results obtained in the experimental application were compared with those of the finite-element analysis of the bridge model. The calibration of the numeric model was utilized depending on the experimental modal analysis results of the reduced-scale bridge by using the RS method. Design of experiments was constructed by using central composite design, and the RS models were generated by performing the genetic aggregation approach. The optimum results between the experimental and numerical analyses were found by using the RS optimization. Then, regional damages created on the scaled model and the changes of dynamic properties of the damaged case were evaluated. The damage location was approximately identified by using the RS method in the calibrated finite-element model. The results demonstrated that the RS-based FE updating approach is an effective way for damage detection and localization in masonry type structures.","PeriodicalId":51181,"journal":{"name":"Structural Engineering and Mechanics","volume":"79 1","pages":"009"},"PeriodicalIF":2.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66126838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.12989/SEM.2021.79.3.347
Chen Xuyong, Xiao Xuehao, Xixuan Bai, Wu Qiaoyun
The dimensional analysis method is used to study the pounding response of two inelastic MDOF (multi-degree-offreedom) structures under simplified earthquake excitation. The improved Kelvin pounding model is adopted to simulate the force and deformation of the collisions during the contact process. The bilinear interstory resistance model is used to describe the inelastic characteristics of the MDOF structures. The expression of dimensionless pounding force and the equation of dimensionless motion during the collision process are derived. Based on the above theoretical derivation, the accuracy of the improved Kelvin model is verified by comparing the pounding responses in the form of spectra between the improved Kelvin model and Kelvin model. The effects of the pounding on the response of the left structure (with a smaller mass and stiffness) are analyzed in different trend (amplification region, suppression region and unaffected region), and the self-similarity of the pounding response for the two inelastic MDOF structures is revealed. The effects of the story mass ratio, post-yield stiffness ratio, yield displacement and structure spacing on the pounding response are studied. The peak displacement response of the left side structure increases with the increasing of story mass ratio and decreases with the increasing of yield displacement and postyield stiffness ratio. With the increasing of structure spacing, the peak displacement decreases in the first spectrum region, and in the second spectrum region, the peak displacement increases. Moreover, the change of the parameters has little effect on the response of the right structure (with a larger mass and stiffness).
{"title":"Dimensional pounding response analysis for adjacent inelastic MDOF structures based on modified Kelvin model","authors":"Chen Xuyong, Xiao Xuehao, Xixuan Bai, Wu Qiaoyun","doi":"10.12989/SEM.2021.79.3.347","DOIUrl":"https://doi.org/10.12989/SEM.2021.79.3.347","url":null,"abstract":"The dimensional analysis method is used to study the pounding response of two inelastic MDOF (multi-degree-offreedom) structures under simplified earthquake excitation. The improved Kelvin pounding model is adopted to simulate the force and deformation of the collisions during the contact process. The bilinear interstory resistance model is used to describe the inelastic characteristics of the MDOF structures. The expression of dimensionless pounding force and the equation of dimensionless motion during the collision process are derived. Based on the above theoretical derivation, the accuracy of the improved Kelvin model is verified by comparing the pounding responses in the form of spectra between the improved Kelvin model and Kelvin model. The effects of the pounding on the response of the left structure (with a smaller mass and stiffness) are analyzed in different trend (amplification region, suppression region and unaffected region), and the self-similarity of the pounding response for the two inelastic MDOF structures is revealed. The effects of the story mass ratio, post-yield stiffness ratio, yield displacement and structure spacing on the pounding response are studied. The peak displacement response of the left side structure increases with the increasing of story mass ratio and decreases with the increasing of yield displacement and postyield stiffness ratio. With the increasing of structure spacing, the peak displacement decreases in the first spectrum region, and in the second spectrum region, the peak displacement increases. Moreover, the change of the parameters has little effect on the response of the right structure (with a larger mass and stiffness).","PeriodicalId":51181,"journal":{"name":"Structural Engineering and Mechanics","volume":"79 1","pages":"347"},"PeriodicalIF":2.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66128463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.12989/SEM.2021.79.3.373
Shaoge Cheng, Yi-Xiu Zhu, Kui Sun, Wei-Ping Zhang
This paper presents a shaking table test carried out on a 1:5 reduced-scale five-story masonry-infilled reinforced concrete (RC) frame model. Multi-level simulated earthquake motions with increasing shaking severity were used as input to deform the model structure from an elastic to a near-collapse state. The dynamic characteristics, acceleration response, displacement response, damage state, energy dissipation behavior and stiffness degradation of each story were summarized for each stage. The tests indicate that cracks developed at the masonry-frame interface during minor shaking that caused infill to separate from the frame; however, its in-plane load bearing capacity was maintained. Moreover, the infill was able to resist infrequent earthquakes without causing instability or collapse of the structure. Thus, it is rational to consider masonry infill as a structural element in the seismic design of structures. Moreover, the story drift ratio of 1/400 can be regarded as the performance criterion for controlling frame structure cracking, and the story drift ratio of 1/100 can be regarded as the performance criterion for the peak bearing capacity of a frame structure. The test results could provide a reference not only for the seismic appraisal of existing buildings, but also for the seismic design of new buildings.
{"title":"Shake-table testing of a 1:5 reduced-scale five-story masonry-infilled reinforced concrete frame structure","authors":"Shaoge Cheng, Yi-Xiu Zhu, Kui Sun, Wei-Ping Zhang","doi":"10.12989/SEM.2021.79.3.373","DOIUrl":"https://doi.org/10.12989/SEM.2021.79.3.373","url":null,"abstract":"This paper presents a shaking table test carried out on a 1:5 reduced-scale five-story masonry-infilled reinforced concrete (RC) frame model. Multi-level simulated earthquake motions with increasing shaking severity were used as input to deform the model structure from an elastic to a near-collapse state. The dynamic characteristics, acceleration response, displacement response, damage state, energy dissipation behavior and stiffness degradation of each story were summarized for each stage. The tests indicate that cracks developed at the masonry-frame interface during minor shaking that caused infill to separate from the frame; however, its in-plane load bearing capacity was maintained. Moreover, the infill was able to resist infrequent earthquakes without causing instability or collapse of the structure. Thus, it is rational to consider masonry infill as a structural element in the seismic design of structures. Moreover, the story drift ratio of 1/400 can be regarded as the performance criterion for controlling frame structure cracking, and the story drift ratio of 1/100 can be regarded as the performance criterion for the peak bearing capacity of a frame structure. The test results could provide a reference not only for the seismic appraisal of existing buildings, but also for the seismic design of new buildings.","PeriodicalId":51181,"journal":{"name":"Structural Engineering and Mechanics","volume":"79 1","pages":"373"},"PeriodicalIF":2.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66128684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.12989/SEM.2021.79.6.665
Xinli Xu, Chunwei Zhang, F. Musharavati, T. Sebaey, Afrasyab Khan
In the present paper, wave propagation behavior of porous temperature-dependent functionally graded curved beams within the thermal environment is analyzed for the first time. A recently-developed method is utilized which considers the reciprocal effect of mass density and Young's modulus in order to explore the influence of porosity. Three different types of temperature variation (uniform temperature change (UTC), linear temperature change (LTC), sinusoidal temperature change (STC)) are employed to study the effect of various thermal loads. Euler-Bernoulli beam theory, also known as classic beam theory is implemented in order to derive kinetic and kinematic relations, and then Hamilton's principle is used to obtain governing equations of porous functionally graded curved beams. The obtained governing equations are analytically solved. Eventually, the influences of various parameters such as wave number, porosity coefficient, various types of temperature change and power index are covered and indicated in a set of illustrations.
{"title":"Wave propagation analysis of porous functionally graded curved beams in the thermal environment","authors":"Xinli Xu, Chunwei Zhang, F. Musharavati, T. Sebaey, Afrasyab Khan","doi":"10.12989/SEM.2021.79.6.665","DOIUrl":"https://doi.org/10.12989/SEM.2021.79.6.665","url":null,"abstract":"In the present paper, wave propagation behavior of porous temperature-dependent functionally graded curved beams within the thermal environment is analyzed for the first time. A recently-developed method is utilized which considers the reciprocal effect of mass density and Young's modulus in order to explore the influence of porosity. Three different types of temperature variation (uniform temperature change (UTC), linear temperature change (LTC), sinusoidal temperature change (STC)) are employed to study the effect of various thermal loads. Euler-Bernoulli beam theory, also known as classic beam theory is implemented in order to derive kinetic and kinematic relations, and then Hamilton's principle is used to obtain governing equations of porous functionally graded curved beams. The obtained governing equations are analytically solved. Eventually, the influences of various parameters such as wave number, porosity coefficient, various types of temperature change and power index are covered and indicated in a set of illustrations.","PeriodicalId":51181,"journal":{"name":"Structural Engineering and Mechanics","volume":"35 1","pages":"665"},"PeriodicalIF":2.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66130157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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