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.2021.78.6.665
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.2021.79.3.347
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.2021.79.6.737
P. Nguyen, Jeong-Hoi Kim, Jong-Byung Oh, Youngshik Park, Dongkyun Lee
This study presents overviews of a first proposed Hidden boundary one-way Rib precast concrete Slab, so-called HRS. In order to investigate bending behaviors of the novel structural system, three specimens manufactured in factory are tested by corresponding static loading protocol experiments. Four-points bending tests in both cases of the presence and absence of topping concrete slabs are performed. Results of the experiment scrutinize how each structural component such as rebars, topping concretes, strand wires can affect the bending behavior of HRS. As regards the main originality of this paper, approximate equations showing flexural strengths for a partially prestressed concrete flagged section, like HRS, are proposed in accordance with several current global and local design standards such as ACI 318, EN: Eurocode 2, PCI, AASHTO 2002, KCI 2012 and CSA A.23. Moreover, this study provides another predicting approach using finite element analysis of MIDAS FEA for analytical performances of specimens. Through these experimental and analytical results, the general characteristic of HRS may be observed and studied for realization in the field of prestressed precast concrete industries for construction.
{"title":"Flexural behaviors assessment of Hidden boundary Rib precast concrete Slab (HRS) with bi-tensional prestress: Experiments, analyses, and formulations","authors":"P. Nguyen, Jeong-Hoi Kim, Jong-Byung Oh, Youngshik Park, Dongkyun Lee","doi":"10.12989/SEM.2021.79.6.737","DOIUrl":"https://doi.org/10.12989/SEM.2021.79.6.737","url":null,"abstract":"This study presents overviews of a first proposed Hidden boundary one-way Rib precast concrete Slab, so-called HRS. In order to investigate bending behaviors of the novel structural system, three specimens manufactured in factory are tested by corresponding static loading protocol experiments. Four-points bending tests in both cases of the presence and absence of topping concrete slabs are performed. Results of the experiment scrutinize how each structural component such as rebars, topping concretes, strand wires can affect the bending behavior of HRS. As regards the main originality of this paper, approximate equations showing flexural strengths for a partially prestressed concrete flagged section, like HRS, are proposed in accordance with several current global and local design standards such as ACI 318, EN: Eurocode 2, PCI, AASHTO 2002, KCI 2012 and CSA A.23. Moreover, this study provides another predicting approach using finite element analysis of MIDAS FEA for analytical performances of specimens. Through these experimental and analytical results, the general characteristic of HRS may be observed and studied for realization in the field of prestressed precast concrete industries for construction.","PeriodicalId":51181,"journal":{"name":"Structural Engineering and Mechanics","volume":"79 1","pages":"737"},"PeriodicalIF":2.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66131086","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.2021.80.1.027
Shiming Liu, Bin Huang, Y. Xie
Shell bridges have attracted extensive interest in engineering research and practice. This paper aims to evaluate the effects of longitudinal and transverse curvatures on the optimal design of the shell bridge. For this purpose, a slant-legged steel shell footbridge with the same initial and target volumes of steel was chosen to build parametric geometric models with different curvature radii, and then topology optimization was carried out using the bi-directional evolutionary structural optimization (BESO) technique to obtain optimized designs with high structural stiffness. Furthermore, linear static analysis and eigenvalue analysis demonstrate that the displacement, von Mises effective stress, and the first-order vertical vibration frequency satisfied all the requirements of design regulations. Numerical results indicate that not only the longitudinal curvature but also the transverse curvature have a significant effect on the optimized designs of steel shell footbridge. While the mean compliance increased with the transverse curvature radius, it first decreased and then increased with the longitudinal curvature radius.
{"title":"Effects of longitudinal and transverse curvatures on optimal design of shell footbridge","authors":"Shiming Liu, Bin Huang, Y. Xie","doi":"10.12989/SEM.2021.80.1.027","DOIUrl":"https://doi.org/10.12989/SEM.2021.80.1.027","url":null,"abstract":"Shell bridges have attracted extensive interest in engineering research and practice. This paper aims to evaluate the effects of longitudinal and transverse curvatures on the optimal design of the shell bridge. For this purpose, a slant-legged steel shell footbridge with the same initial and target volumes of steel was chosen to build parametric geometric models with different curvature radii, and then topology optimization was carried out using the bi-directional evolutionary structural optimization (BESO) technique to obtain optimized designs with high structural stiffness. Furthermore, linear static analysis and eigenvalue analysis demonstrate that the displacement, von Mises effective stress, and the first-order vertical vibration frequency satisfied all the requirements of design regulations. Numerical results indicate that not only the longitudinal curvature but also the transverse curvature have a significant effect on the optimized designs of steel shell footbridge. While the mean compliance increased with the transverse curvature radius, it first decreased and then increased with the longitudinal curvature radius.","PeriodicalId":51181,"journal":{"name":"Structural Engineering and Mechanics","volume":"80 1","pages":"27"},"PeriodicalIF":2.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66131096","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.2021.79.5.653
Mehran Agha Mohammad Pour, H. Ovesy
The aim of this paper is to study the effects of linear viscoelastic behavior on dynamic buckling response of imperfect composite laminated plates subjected to in-plane dynamic loads by implementing semi-analytical finite strip method (FSM). The semi-analytical FSM converges with a comparatively small number of strips and correspondingly small number of degrees of freedom. Thus, it is usually implemented more easily and faster than many other computational methods. The governing equations are derived by using classical laminated plate theory (CLPT) and the behavior of plate is assumed to be geometrically nonlinear through Von-Karman assumptions. The Newmark's implicit time integration method in conjunction with the Newton-Raphson iteration are employed to solve the nonlinear governing equation. A Kelvin-Voigt viscoelastic model is considered, and the effects of viscosity coefficient, thickness of the layers of the composite plate and boundary conditions on the nonlinear dynamic buckling response are discussed. In order to justify the accuracy of the results, some of them are verified against those available in other sources. It is also shown that the nonlinear dynamic buckling response of an imperfect viscoelastic composite laminated plate is significantly different from the elastic one by considering different viscosity coefficients.
{"title":"Nonlinear dynamic buckling analysis of imperfect viscoelastic composite laminated plates","authors":"Mehran Agha Mohammad Pour, H. Ovesy","doi":"10.12989/SEM.2021.79.5.653","DOIUrl":"https://doi.org/10.12989/SEM.2021.79.5.653","url":null,"abstract":"The aim of this paper is to study the effects of linear viscoelastic behavior on dynamic buckling response of imperfect composite laminated plates subjected to in-plane dynamic loads by implementing semi-analytical finite strip method (FSM). The semi-analytical FSM converges with a comparatively small number of strips and correspondingly small number of degrees of freedom. Thus, it is usually implemented more easily and faster than many other computational methods. The governing equations are derived by using classical laminated plate theory (CLPT) and the behavior of plate is assumed to be geometrically nonlinear through Von-Karman assumptions. The Newmark's implicit time integration method in conjunction with the Newton-Raphson iteration are employed to solve the nonlinear governing equation. A Kelvin-Voigt viscoelastic model is considered, and the effects of viscosity coefficient, thickness of the layers of the composite plate and boundary conditions on the nonlinear dynamic buckling response are discussed. In order to justify the accuracy of the results, some of them are verified against those available in other sources. It is also shown that the nonlinear dynamic buckling response of an imperfect viscoelastic composite laminated plate is significantly different from the elastic one by considering different viscosity coefficients.","PeriodicalId":51181,"journal":{"name":"Structural Engineering and Mechanics","volume":"79 1","pages":"653"},"PeriodicalIF":2.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66130584","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.2021.77.6.721
H. Mortezaie, R. Zamanian
The seismic analysis of structures without applying the effects of soil can undermine functional objectives of structure so that it can affect all the desired purposes at the design and control stages of the structure. In this research, employing OpenSees and MATLAB software simultaneously and developing a definite three-dimensional finite element model of a highrise concrete structure, designed using performance-based plastic design approach, the performance of Tuned Mass Damper (TMD) and Active Mass Damper (AMD) is both examined and compared. Moreover some less noted aspects such as nonlinear interaction of soil and structure, uplift, nonlinear behavior of structure and structural torsion have received more attention. For this purpose, the analysis of time history on the structural model has been performed under 22 far-field accelerogram records. Examining a full range of all structural seismic responses, including lateral displacement, acceleration, inter-story drift, lost plastic energy, number of plastic hinges, story shear force and uplift. The results indicate that TMD performs better than AMD except for lateral displacement and inter-story drift to control other structural responses. Because on the one hand, nonlinear structural parameters and soil-structure interaction have been added and on the other hand, the restriction on the control force applied that leads up to saturation phenomenon in the active control system affect the performance of AMD. Moreover, the control force applied by structural control system has created undesirable acceleration and shear force in the structure.
{"title":"Seismic control of concrete buildings with nonlinear behavior, considering soil structure interaction using AMD and TMD","authors":"H. Mortezaie, R. Zamanian","doi":"10.12989/SEM.2021.77.6.721","DOIUrl":"https://doi.org/10.12989/SEM.2021.77.6.721","url":null,"abstract":"The seismic analysis of structures without applying the effects of soil can undermine functional objectives of structure so that it can affect all the desired purposes at the design and control stages of the structure. In this research, employing OpenSees and MATLAB software simultaneously and developing a definite three-dimensional finite element model of a highrise concrete structure, designed using performance-based plastic design approach, the performance of Tuned Mass Damper (TMD) and Active Mass Damper (AMD) is both examined and compared. Moreover some less noted aspects such as nonlinear interaction of soil and structure, uplift, nonlinear behavior of structure and structural torsion have received more attention. For this purpose, the analysis of time history on the structural model has been performed under 22 far-field accelerogram records. Examining a full range of all structural seismic responses, including lateral displacement, acceleration, inter-story drift, lost plastic energy, number of plastic hinges, story shear force and uplift. The results indicate that TMD performs better than AMD except for lateral displacement and inter-story drift to control other structural responses. Because on the one hand, nonlinear structural parameters and soil-structure interaction have been added and on the other hand, the restriction on the control force applied that leads up to saturation phenomenon in the active control system affect the performance of AMD. Moreover, the control force applied by structural control system has created undesirable acceleration and shear force in the structure.","PeriodicalId":51181,"journal":{"name":"Structural Engineering and Mechanics","volume":"77 1","pages":"721-734"},"PeriodicalIF":2.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66123631","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}
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