Pub Date : 2021-01-01DOI: 10.12989/SCS.2021.39.5.615
Fahimeh Rashed Saghavaz, G. Payganeh, K. M. Fard
The main purpose of the present work was to study the dynamic instability of a three-layered, thick composite sandwich beam with the functionally graded (FG) flexible core subjected to an axial compressive follower force. Flutter instability of a sandwich cantilever beam was analyzed using the high-order theory of sandwich beams, for the first time. The governing equations in general for sandwich beams with an FG core were extracted and could be used for all types of sandwich beams with any types of face sheets and cores. A polynomial function is considered for the vertical distribution of the displacement field in the core layer along the thickness, based on the results of the first Frosting's higher order model. The governing partial differential equations and the equations of boundary conditions of the dynamic system are derived using Hamilton's principle. By applying the boundary conditions and numerical solution methods of squares quadrature, the beam flutter phenomenon is studied. In addition, the effects of different geometrical and material parameters on the flutter threshold were investigated. The results showed that the responses of the dynamic instability of the system were influenced by the follower force, the coefficients of FGs and the geometrical parameters like the core thickness. Comparison of the present results with the published results in the literature for the special case confirmed the accuracy of the proposed theory. The results showed that the follower force of the flutter phenomenon threshold for long beams tends to the corresponding results in the Timoshenko beam.
{"title":"Flutter phenomenon in composite sandwich beams with flexible core under follower force","authors":"Fahimeh Rashed Saghavaz, G. Payganeh, K. M. Fard","doi":"10.12989/SCS.2021.39.5.615","DOIUrl":"https://doi.org/10.12989/SCS.2021.39.5.615","url":null,"abstract":"The main purpose of the present work was to study the dynamic instability of a three-layered, thick composite sandwich beam with the functionally graded (FG) flexible core subjected to an axial compressive follower force. Flutter instability of a sandwich cantilever beam was analyzed using the high-order theory of sandwich beams, for the first time. The governing equations in general for sandwich beams with an FG core were extracted and could be used for all types of sandwich beams with any types of face sheets and cores. A polynomial function is considered for the vertical distribution of the displacement field in the core layer along the thickness, based on the results of the first Frosting's higher order model. The governing partial differential equations and the equations of boundary conditions of the dynamic system are derived using Hamilton's principle. By applying the boundary conditions and numerical solution methods of squares quadrature, the beam flutter phenomenon is studied. In addition, the effects of different geometrical and material parameters on the flutter threshold were investigated. The results showed that the responses of the dynamic instability of the system were influenced by the follower force, the coefficients of FGs and the geometrical parameters like the core thickness. Comparison of the present results with the published results in the literature for the special case confirmed the accuracy of the proposed theory. The results showed that the follower force of the flutter phenomenon threshold for long beams tends to the corresponding results in the Timoshenko beam.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"39 1","pages":"615"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66593024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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/SCS.2021.39.6.737
Mahdi Bayat, A. H. Kosarieh, M. Javanmard
Soil nailing is one of the most common and important techniques to exchange conventional retaining systems for deep excavation. This approach contains a significant saving in cost and time of construction compared to conventional retaining systems. In this paper, an attempt has been made to evaluate the dynamical response of a deep vertical excavation on ground of 8 m height using soil nail wall. It has been tried to investigate the effects of different modeling approaches on the dynamic response of soil-nailed walls by considering the three behavioral methods; Mohr Coulomb (MC), hardening soil (HS) and hardening soil model with Small-Strain stiffness ensued from small strains (HSS). Nonlinear time history analysis has been implemented to compare the displacements under the sinus excitation with 0.5, 1, and 1.5 Hz with PGA= 0.3 g. Different points along the height of the wall are selected and considered. At the last part of this paper, incremental dynamic analysis (IDA) was implemented to the soil nail wall to consider the effect of the different earthquake records on the response of the wall. The IDA curve is also presented for the considered soil nail wall.
{"title":"Nonlinear dynamic analysis of soil nail walls considering different modeling approaches","authors":"Mahdi Bayat, A. H. Kosarieh, M. Javanmard","doi":"10.12989/SCS.2021.39.6.737","DOIUrl":"https://doi.org/10.12989/SCS.2021.39.6.737","url":null,"abstract":"Soil nailing is one of the most common and important techniques to exchange conventional retaining systems for deep excavation. This approach contains a significant saving in cost and time of construction compared to conventional retaining systems. In this paper, an attempt has been made to evaluate the dynamical response of a deep vertical excavation on ground of 8 m height using soil nail wall. It has been tried to investigate the effects of different modeling approaches on the dynamic response of soil-nailed walls by considering the three behavioral methods; Mohr Coulomb (MC), hardening soil (HS) and hardening soil model with Small-Strain stiffness ensued from small strains (HSS). Nonlinear time history analysis has been implemented to compare the displacements under the sinus excitation with 0.5, 1, and 1.5 Hz with PGA= 0.3 g. Different points along the height of the wall are selected and considered. At the last part of this paper, incremental dynamic analysis (IDA) was implemented to the soil nail wall to consider the effect of the different earthquake records on the response of the wall. The IDA curve is also presented for the considered soil nail wall.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"39 1","pages":"737"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66593328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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/SCS.2021.39.6.685
Yan Cao, Y. Zandi, Alireza Sadighi Agdas, Qiangfeng Wang, Xueming Qian, Leijie Fu, Karzan Wakil, A. Selmi, A. Issakhov, Á. Roco-Videla
This paper is aimed to review the use of artificial intelligence (AI) algorithms in diverse civil engineering applications such as predicting and evaluating the different parameters of composite beams and shear connectors and determining the compressive strength of concrete. Also, the application of AI methods especially artificial neural network (ANN) in construction engineering and management including prediction and estimation, decision-making, classification or selection, optimization and risk analysis and safety has been thoroughly discussed. Furthermore, the integration of Artificial Neural network (ANN) with other soft computing methods, such as Backpropagation (BP), imperialist competitive algorithm (ICA), support vector regression (SVR), back-propagation neural network (BPNN), Genetic Algorithms (GA) and Multilayer feed forward (MLFF) has been reviewed. It has been reported that the combination of ANN with other intelligence algorithms leads to providing more accurate results. Moreover, the performance of ANN with other soft computing techniques, such as BP, BPNN, SVR, GA, ICA, and MLFF in various fields has been compared and ANN in many cases had superiority over other models.
{"title":"A review study of application of artificial intelligence in construction management and composite beams","authors":"Yan Cao, Y. Zandi, Alireza Sadighi Agdas, Qiangfeng Wang, Xueming Qian, Leijie Fu, Karzan Wakil, A. Selmi, A. Issakhov, Á. Roco-Videla","doi":"10.12989/SCS.2021.39.6.685","DOIUrl":"https://doi.org/10.12989/SCS.2021.39.6.685","url":null,"abstract":"This paper is aimed to review the use of artificial intelligence (AI) algorithms in diverse civil engineering applications such as predicting and evaluating the different parameters of composite beams and shear connectors and determining the compressive strength of concrete. Also, the application of AI methods especially artificial neural network (ANN) in construction engineering and management including prediction and estimation, decision-making, classification or selection, optimization and risk analysis and safety has been thoroughly discussed. Furthermore, the integration of Artificial Neural network (ANN) with other soft computing methods, such as Backpropagation (BP), imperialist competitive algorithm (ICA), support vector regression (SVR), back-propagation neural network (BPNN), Genetic Algorithms (GA) and Multilayer feed forward (MLFF) has been reviewed. It has been reported that the combination of ANN with other intelligence algorithms leads to providing more accurate results. Moreover, the performance of ANN with other soft computing techniques, such as BP, BPNN, SVR, GA, ICA, and MLFF in various fields has been compared and ANN in many cases had superiority over other models.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"39 1","pages":"685"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66593345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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/SCS.2021.39.5.599
M. Rezaiee-Pajand, A. Masoodi, A. Alepaighambar
This study deals with the Lateral-Torsional Buckling (LTB) of a mono-symmetric tapered I-beam, in which the cross-section is varying longitudinally. To obtain the buckling moment, two concentrated bending moments should be applied at the two ends of the structure. This structure is made of Functionally Graded Material (FGM). The Young' s and shear modules change linearly along the longitudinal direction of the beam. It is considered that this tapered beam is laterally restrained continuously, by using torsional springs. Furthermore, two rotational bending springs are employed at the two structural ends. To achieve the buckling moment, Ritz solution method is utilized. The response of critical buckling moment of the beam is obtained by minimizing the total potential energy relation. The lateral and torsional displacement fields of the beam are interpolated by harmonic functions. These functions satisfy the boundary conditions. Two different support conditions are considered in this study. The obtained formulation is validated by solving benchmark problems. Moreover, some numerical studies are implemented to show the accuracy, efficiency and high performance of the proposed formulation.
{"title":"Critical buckling moment of functionally graded tapered mono-symmetric I-beam","authors":"M. Rezaiee-Pajand, A. Masoodi, A. Alepaighambar","doi":"10.12989/SCS.2021.39.5.599","DOIUrl":"https://doi.org/10.12989/SCS.2021.39.5.599","url":null,"abstract":"This study deals with the Lateral-Torsional Buckling (LTB) of a mono-symmetric tapered I-beam, in which the cross-section is varying longitudinally. To obtain the buckling moment, two concentrated bending moments should be applied at the two ends of the structure. This structure is made of Functionally Graded Material (FGM). The Young' s and shear modules change linearly along the longitudinal direction of the beam. It is considered that this tapered beam is laterally restrained continuously, by using torsional springs. Furthermore, two rotational bending springs are employed at the two structural ends. To achieve the buckling moment, Ritz solution method is utilized. The response of critical buckling moment of the beam is obtained by minimizing the total potential energy relation. The lateral and torsional displacement fields of the beam are interpolated by harmonic functions. These functions satisfy the boundary conditions. Two different support conditions are considered in this study. The obtained formulation is validated by solving benchmark problems. Moreover, some numerical studies are implemented to show the accuracy, efficiency and high performance of the proposed formulation.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"39 1","pages":"599"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66593463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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/SCS.2021.40.1.121
M. A. Hadianfard, Mahboobe Namjoo, Morteza Boroumand, Sareh Akbarpoor
A structure undergoes progressive collapse when a primary structural element fails, leading to damage of either a large part or even the entire structure. Beam-column connections are one of the major contributing structural elements which significantly affect the performance of the structure. Undesirable performance and damage to these connections can result in local failure and, in turn, lead to progressive failure. In the present research, behaviors of some beam-column connections were empirically and numerically assessed subject to column removal scenario. A number of tests were performed on some welded top and seat angle connections. Then, numerical models were created and validated by the experimental results. It was observed that the results of finite element analyses very well correspond to the test results. Moreover, parametric studies were done using finite element analysis. Behavior, failure limit states, and formation of the catenary action were investigated. Results demonstrate that adding a web plate or a web angle could be an appropriate method for upgrading the connection behavior. Furthermore, an increase in the angle thickness and length of the angle leg attached to the column can result in higher resistance to progressive collapse.
{"title":"Investigation of welded top and seat angle connections under column removal event","authors":"M. A. Hadianfard, Mahboobe Namjoo, Morteza Boroumand, Sareh Akbarpoor","doi":"10.12989/SCS.2021.40.1.121","DOIUrl":"https://doi.org/10.12989/SCS.2021.40.1.121","url":null,"abstract":"A structure undergoes progressive collapse when a primary structural element fails, leading to damage of either a large part or even the entire structure. Beam-column connections are one of the major contributing structural elements which significantly affect the performance of the structure. Undesirable performance and damage to these connections can result in local failure and, in turn, lead to progressive failure. In the present research, behaviors of some beam-column connections were empirically and numerically assessed subject to column removal scenario. A number of tests were performed on some welded top and seat angle connections. Then, numerical models were created and validated by the experimental results. It was observed that the results of finite element analyses very well correspond to the test results. Moreover, parametric studies were done using finite element analysis. Behavior, failure limit states, and formation of the catenary action were investigated. Results demonstrate that adding a web plate or a web angle could be an appropriate method for upgrading the connection behavior. Furthermore, an increase in the angle thickness and length of the angle leg attached to the column can result in higher resistance to progressive collapse.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"40 1","pages":"121"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66594413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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/SCS.2021.40.2.203
Yaobing Zhao, Panpan Zheng
The present study is dealing with a geometrically nonlinear model of the suspended cable subjected to multi-frequency excitations. In particular, two of the super, sub-harmonic, and combination resonances are excited simultaneously here. The nonlinear integro-differential equations of the suspended cable are introduced, together with the Galerkin method, to obtain a reduced-order model, whose responses are investigated by solving the reduced ordinary differential equations. Then, the obtained single-mode discretization equations are solved using the method of multiple scales in the frequency regions of three simultaneous resonant cases, with the stability characteristics determined. Effects of parameters on resonance characteristics are carried out by investigating several numerical examples. Numerical results demonstrate that the two-frequency excitation has significant influences on the dynamical behaviors of the nonlinear system. Each harmonic excitation component's contribution to the overall resonant responses is mainly dependent on its excitation amplitude. The stable steady-state solutions are confirmed by using numerical integration, and the number of steady-state solutions varies from one to seven as to different parameters of the system in simultaneous resonances. Besides, it is of great significance to include the effects of excitation phase differences on nonlinear vibration characteristics.
{"title":"Parameter analyses of suspended cables subjected to simultaneous combination, super and sub-harmonic excitations","authors":"Yaobing Zhao, Panpan Zheng","doi":"10.12989/SCS.2021.40.2.203","DOIUrl":"https://doi.org/10.12989/SCS.2021.40.2.203","url":null,"abstract":"The present study is dealing with a geometrically nonlinear model of the suspended cable subjected to multi-frequency excitations. In particular, two of the super, sub-harmonic, and combination resonances are excited simultaneously here. The nonlinear integro-differential equations of the suspended cable are introduced, together with the Galerkin method, to obtain a reduced-order model, whose responses are investigated by solving the reduced ordinary differential equations. Then, the obtained single-mode discretization equations are solved using the method of multiple scales in the frequency regions of three simultaneous resonant cases, with the stability characteristics determined. Effects of parameters on resonance characteristics are carried out by investigating several numerical examples. Numerical results demonstrate that the two-frequency excitation has significant influences on the dynamical behaviors of the nonlinear system. Each harmonic excitation component's contribution to the overall resonant responses is mainly dependent on its excitation amplitude. The stable steady-state solutions are confirmed by using numerical integration, and the number of steady-state solutions varies from one to seven as to different parameters of the system in simultaneous resonances. Besides, it is of great significance to include the effects of excitation phase differences on nonlinear vibration characteristics.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"27 1","pages":"203"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66594692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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/SCS.2021.40.2.217
Youde Wang, Tao Shi, Biao Nie, Hao Wang, Shan-hua Xu
Steel structures exposed to general atmosphere for a long time are highly susceptible to corrosion damage, which would lead to the degradation of service performance of the components and even structures. This article focuses on the effect of corrosion on the seismic performance of steel column. The accelerated corrosion tests in general atmosphere were conducted on 7 H-shaped steel columns and 20 steel plates. Then the obtained plate specimens were subjected to monotonic tensile tests and cyclic loading tests, and the steel columns were subjected to pseudo-static tests, respectively, to study the effects of corrosion on their mechanical properties and seismic performance. Then, a simplified three-dimensional finite element model (FEM) capable of accurately simulating the hysteretic response of corroded steel columns under low-cycle loading was established. Experimental results indicated that the yield strength, tensile strength, elastic modulus and peak strain of corroded steel plate decreased linearly with the proposed corrosion damage parameter Dn, and the energy dissipations under low-cycle loading were significantly reduced. There is a correlation between the cyclic hardening parameters of corroded steel and the yield-tensile strength difference (SD), and then a simplified formula was proposed. Corrosion could result in the premature entrance of each loading stage of corroded columns and the deterioration of buckling deformation range, bearing capacity and energy dissipation, etc. In addition, a larger axial compression ratio (CR) would further accelerate the failure process of corroded columns. The parametric finite element analysis (FEA) indicated that greater damage was found for steel columns with non-uniform corrosion, and hysteretic performance degraded more significantly when corrosion distributed at flanges or foot zone.
{"title":"Seismic performance of steel columns corroded in general atmosphere","authors":"Youde Wang, Tao Shi, Biao Nie, Hao Wang, Shan-hua Xu","doi":"10.12989/SCS.2021.40.2.217","DOIUrl":"https://doi.org/10.12989/SCS.2021.40.2.217","url":null,"abstract":"Steel structures exposed to general atmosphere for a long time are highly susceptible to corrosion damage, which would lead to the degradation of service performance of the components and even structures. This article focuses on the effect of corrosion on the seismic performance of steel column. The accelerated corrosion tests in general atmosphere were conducted on 7 H-shaped steel columns and 20 steel plates. Then the obtained plate specimens were subjected to monotonic tensile tests and cyclic loading tests, and the steel columns were subjected to pseudo-static tests, respectively, to study the effects of corrosion on their mechanical properties and seismic performance. Then, a simplified three-dimensional finite element model (FEM) capable of accurately simulating the hysteretic response of corroded steel columns under low-cycle loading was established. Experimental results indicated that the yield strength, tensile strength, elastic modulus and peak strain of corroded steel plate decreased linearly with the proposed corrosion damage parameter Dn, and the energy dissipations under low-cycle loading were significantly reduced. There is a correlation between the cyclic hardening parameters of corroded steel and the yield-tensile strength difference (SD), and then a simplified formula was proposed. Corrosion could result in the premature entrance of each loading stage of corroded columns and the deterioration of buckling deformation range, bearing capacity and energy dissipation, etc. In addition, a larger axial compression ratio (CR) would further accelerate the failure process of corroded columns. The parametric finite element analysis (FEA) indicated that greater damage was found for steel columns with non-uniform corrosion, and hysteretic performance degraded more significantly when corrosion distributed at flanges or foot zone.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"40 1","pages":"217"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66594745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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/SCS.2021.40.3.339
Jianfeng Chen, Mingqi Chen, Yongqiang Shen, J. Shao, Xinxin Yang
In this paper, the axial compressive properties of cold-formed steel lipped channel stub columns strengthened by rebars or steel strips are experimentally studied. The experiment included two sections. A kind of columns with local buckling is reinforced longitudinally by steel strips at the web. The other is the columns with distorted buckling, which is reinforced longitudinally by steel bars at the curling edge. The failure mode, deformation characteristics, ultimate bearing capacity and load displacement curve of the specimen are obtained through the experiment. On the basis of the experiment, the calculation results of theoretical axial bearing capacity of cold-formed steel lipped channel stub columns in Chinese, North American and Australian code are compared and analyzed. Research indicates: First, the cold-formed steel lipped channel stub columns strengthened by steel bars or steel strips can effectively improve the compressive bearing capacity of the specimen. Secondly, when the initial stress ratio of specimen is less than 0.3, the reinforcement effect is ideal. Thirdly, the three standards don't stipulate the calculation of theoretical bearing capacity of the specimen strengthened after loading, so there is a large deviation between the theoretical calculation value and the test value.
{"title":"Experimental study on cold-formed lipped channel stub columns reinforced by steel bars or steel strips","authors":"Jianfeng Chen, Mingqi Chen, Yongqiang Shen, J. Shao, Xinxin Yang","doi":"10.12989/SCS.2021.40.3.339","DOIUrl":"https://doi.org/10.12989/SCS.2021.40.3.339","url":null,"abstract":"In this paper, the axial compressive properties of cold-formed steel lipped channel stub columns strengthened by rebars or steel strips are experimentally studied. The experiment included two sections. A kind of columns with local buckling is reinforced longitudinally by steel strips at the web. The other is the columns with distorted buckling, which is reinforced longitudinally by steel bars at the curling edge. The failure mode, deformation characteristics, ultimate bearing capacity and load displacement curve of the specimen are obtained through the experiment. On the basis of the experiment, the calculation results of theoretical axial bearing capacity of cold-formed steel lipped channel stub columns in Chinese, North American and Australian code are compared and analyzed. Research indicates: First, the cold-formed steel lipped channel stub columns strengthened by steel bars or steel strips can effectively improve the compressive bearing capacity of the specimen. Secondly, when the initial stress ratio of specimen is less than 0.3, the reinforcement effect is ideal. Thirdly, the three standards don't stipulate the calculation of theoretical bearing capacity of the specimen strengthened after loading, so there is a large deviation between the theoretical calculation value and the test value.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"40 1","pages":"339"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66595372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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/SCS.2021.40.4.581
S.M. Hosseini, F. Mashiri, O. Mirza, B. Hart
The purpose of this research is to identify more efficient and reliable connection methods to design a composite steel/concrete structural system with a focus on sustainability. While using innovative blind bolt shear connectors into substitute for the welded stud brings several benefits regarding constructability and sustainability, research contributions on the high strength blind bolt shear connector are very limited. Therefore, in this study, several push-out test specimens were carried out, in accordance with the Eurocode 4 standards, for both the traditional welded stud and the blind bolt shear connector, to determine the ultimate capacity, ductility, stiffness, stress-strain and load versus slip performance. In addition, finite element analysis has been done on the two types of shear connectors to determine the factors influencing static strength of shear connectors. The feasibility and accuracy of the 3-D finite element model developed in this work was validated by comparing with experimental results obtained from push-out tests. Experimental and finite element modelling results revealed that the blind bolt shear connectors would be an appropriate alternative to the traditional welded stud for sustainable purposes under static loading conditions.
{"title":"Structural performance of steel-concrete composite bridges utilising innovative blind bolt shear connectors","authors":"S.M. Hosseini, F. Mashiri, O. Mirza, B. Hart","doi":"10.12989/SCS.2021.40.4.581","DOIUrl":"https://doi.org/10.12989/SCS.2021.40.4.581","url":null,"abstract":"The purpose of this research is to identify more efficient and reliable connection methods to design a composite steel/concrete structural system with a focus on sustainability. While using innovative blind bolt shear connectors into substitute for the welded stud brings several benefits regarding constructability and sustainability, research contributions on the high strength blind bolt shear connector are very limited. Therefore, in this study, several push-out test specimens were carried out, in accordance with the Eurocode 4 standards, for both the traditional welded stud and the blind bolt shear connector, to determine the ultimate capacity, ductility, stiffness, stress-strain and load versus slip performance. In addition, finite element analysis has been done on the two types of shear connectors to determine the factors influencing static strength of shear connectors. The feasibility and accuracy of the 3-D finite element model developed in this work was validated by comparing with experimental results obtained from push-out tests. Experimental and finite element modelling results revealed that the blind bolt shear connectors would be an appropriate alternative to the traditional welded stud for sustainable purposes under static loading conditions.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"40 1","pages":"581"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66596159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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/SCS.2021.40.5.709
S. Gao, Y. Pang, H. Ge
This paper aims to propose a simplified method for predicting ultimate strength and ductility behavior of locally corroded steel box-section bridge piers. Firstly, the accuracy of the proposed 3-D elastoplastic finite element model for the steel piers subjected to a constant vertical load and cyclic lateral loading is verified by comparing the analytical results with test results. Then, a series of parametric study is carried out to investigate the effect of corrosion height ratio and corrosion thickness ratio of steel plates on the ultimate strength and ductility behavior of these piers. Finally, by establishing 2-D beam-column element models and comparing the calculation results with those of the 3-D models, correction coefficients for the ductility ratio and ultimate strength of 2-D beam-column element model under local corrosion are proposed. The research results indicate that there exists a most unfavorable corrosion height which makes the ductility ratio of steel piers the smallest. The ultimate strength of the steel piers will not have a distinct degradation when the corrosion height becomes larger than 0.5Ld. The correction coefficient formula for ductility ratio with respect to different aspect ratio of steel piers, and the linear relationship between correction strength coefficient and the corrosion thickness ratio are proposed. Correction coefficients for 2-D beam-column element model under the most unfavorable corrosion height are proven to have a rational accuracy, which provides a fast and simplified method to evaluate the ultimate strength and ductility behavior of such steel piers under local corrosion.
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