Pub Date : 2021-01-01DOI: 10.12989/SCS.2021.38.2.165
Yitian Zhang, B. Shan, T. Kang, Yan Xiao
Existing research on confined concrete filled steel tubular (CCFT) columns has been mainly focused on static or cyclic loading. In this paper, square section CCFT and CFT columns were tested under both static and impact loading, using a 10,000 kN capacity compression test machine and a drop weight testing equipment. Research parameters included bonded and unbonded fiber reinforced polymer (FRP) wraps, with carbon, basalt and glass FRPs (or CFRP, BFRP, and GFRP), respectively. Time history curves for impact force and steel strain observed are discussed in detail. Experimental results show that the failure modes of specimens under impact testing were characterized by local buckling of the steel tube and cracking at the corners, for both CCFT and CFT columns, similar to those under static loading. For both static and impact loading, the FRP wraps could improve the behavior and increase the loading capacity. To analyze the dynamic behavior of the composite columns, a finite element, FE, model was established in LS-DYNA. A simplified method that is compared favorably with test results is also proposed to predict the impact load capacity of square CCFT columns.
{"title":"Axial impact behavior of confined concrete filled square steel tubes using fiber reinforced polymer","authors":"Yitian Zhang, B. Shan, T. Kang, Yan Xiao","doi":"10.12989/SCS.2021.38.2.165","DOIUrl":"https://doi.org/10.12989/SCS.2021.38.2.165","url":null,"abstract":"Existing research on confined concrete filled steel tubular (CCFT) columns has been mainly focused on static or cyclic loading. In this paper, square section CCFT and CFT columns were tested under both static and impact loading, using a 10,000 kN capacity compression test machine and a drop weight testing equipment. Research parameters included bonded and unbonded fiber reinforced polymer (FRP) wraps, with carbon, basalt and glass FRPs (or CFRP, BFRP, and GFRP), respectively. Time history curves for impact force and steel strain observed are discussed in detail. Experimental results show that the failure modes of specimens under impact testing were characterized by local buckling of the steel tube and cracking at the corners, for both CCFT and CFT columns, similar to those under static loading. For both static and impact loading, the FRP wraps could improve the behavior and increase the loading capacity. To analyze the dynamic behavior of the composite columns, a finite element, FE, model was established in LS-DYNA. A simplified method that is compared favorably with test results is also proposed to predict the impact load capacity of square CCFT columns.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"38 1","pages":"165-176"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66588588","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.2021.38.3.281
Kaiyue Sun, N. Zhang, Xiao Liu, Yan Tao
An equivalent single-layer theory (EST) is put forward for analyzing free vibrations of steel-concrete composite beams (SCCB) based on a higher-order beam theory. In the EST, the effect of partial interaction between sub-beams and the transverse shear deformation are taken into account. After using the interlaminar shear force continuity condition and the shear stress free conditions at the top and bottom surface, the displacement function of the EST does not contain the first derivatives of transverse displacement. Therefore, the C0 interpolation functions are just demanded during its finite element implementation. Finally, the EST is validated by comparing the results of two simply-supported steel-concrete composite beams which are tested in laboratory and calculated by ANSYS software. Then, the influencing factors for free vibrations of SCCB are analyzed, such as, different boundary conditions, depth to span ratio, high-order shear terms, and interfacial shear connector stiffness.
{"title":"An equivalent single-layer theory for free vibration analysis of steel-concrete composite beams","authors":"Kaiyue Sun, N. Zhang, Xiao Liu, Yan Tao","doi":"10.12989/SCS.2021.38.3.281","DOIUrl":"https://doi.org/10.12989/SCS.2021.38.3.281","url":null,"abstract":"An equivalent single-layer theory (EST) is put forward for analyzing free vibrations of steel-concrete composite beams (SCCB) based on a higher-order beam theory. In the EST, the effect of partial interaction between sub-beams and the transverse shear deformation are taken into account. After using the interlaminar shear force continuity condition and the shear stress free conditions at the top and bottom surface, the displacement function of the EST does not contain the first derivatives of transverse displacement. Therefore, the C0 interpolation functions are just demanded during its finite element implementation. Finally, the EST is validated by comparing the results of two simply-supported steel-concrete composite beams which are tested in laboratory and calculated by ANSYS software. Then, the influencing factors for free vibrations of SCCB are analyzed, such as, different boundary conditions, depth to span ratio, high-order shear terms, and interfacial shear connector stiffness.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"38 1","pages":"281-291"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66589296","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.2021.38.5.583
Mashhour A. Alazwari, A. Abdelrahman, A. Wagih, M. A. Eltaher, H. Abd-El-Mottaleb
This article develops a nonclassical model to analyze bending response of squared perforated microbeams considering the coupled effect of microstructure and surface stress under different loading and boundary conditions, those are not be studied before. The corresponding material and geometrical characteristics of regularly squared perforated beams relative to fully filled beam are obtained analytically. The modified couple stress and the modified Gurtin-Murdoch surface elasticity models are adopted to incorporate the microstructure as well as the surface energy effects. The differential equations of equilibrium including the Poisson's effect are derived based on minimum potential energy. Exact closed form solution is obtained for bending behavior of the proposed model considering the classical and nonclassical boundary conditions for both uniformly distributed and concentrated loads. The proposed model is verified with results available in the literature. Influences of the microstructure length scale parameter, surface energy, beam thickness, boundary and loading conditions on the bending behavior of perforated microbeams are investigated. It is observed that microstructure and surface parameters are vital in investigation of the bending behavior of perforated microbeams. The obtained results are supportive for the design, analysis and manufacturing of perforated nanobeams that commonly used in nanoactuators, nanoswitches, MEMS and NEMS systems.
{"title":"Static analysis of cutout microstructures incorporating the microstructure and surface effects","authors":"Mashhour A. Alazwari, A. Abdelrahman, A. Wagih, M. A. Eltaher, H. Abd-El-Mottaleb","doi":"10.12989/SCS.2021.38.5.583","DOIUrl":"https://doi.org/10.12989/SCS.2021.38.5.583","url":null,"abstract":"This article develops a nonclassical model to analyze bending response of squared perforated microbeams considering the coupled effect of microstructure and surface stress under different loading and boundary conditions, those are not be studied before. The corresponding material and geometrical characteristics of regularly squared perforated beams relative to fully filled beam are obtained analytically. The modified couple stress and the modified Gurtin-Murdoch surface elasticity models are adopted to incorporate the microstructure as well as the surface energy effects. The differential equations of equilibrium including the Poisson's effect are derived based on minimum potential energy. Exact closed form solution is obtained for bending behavior of the proposed model considering the classical and nonclassical boundary conditions for both uniformly distributed and concentrated loads. The proposed model is verified with results available in the literature. Influences of the microstructure length scale parameter, surface energy, beam thickness, boundary and loading conditions on the bending behavior of perforated microbeams are investigated. It is observed that microstructure and surface parameters are vital in investigation of the bending behavior of perforated microbeams. The obtained results are supportive for the design, analysis and manufacturing of perforated nanobeams that commonly used in nanoactuators, nanoswitches, MEMS and NEMS systems.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"38 1","pages":"583-597"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66590288","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.2021.39.3.337
Zongping Chen, Deyi Xu, Jinjun Xu, Ni Wang
The study presented experimental and numerical investigation on the seismic performance of steel reinforced concrete (SRC) L-shaped column- reinforced concrete (RC) beam joints. Various parameters described as steel configuration form, axial compressive ratio, loading angle, and the existence of slab were examined through 4 planar joints and 7 spatial joints. The characteristics of the load-displacement response included the bearing capacity, ductility, story drift ratio, energy-dissipating capacity, and stiffness degradation were analyzed. The results showed that shear failure and flexural failure in the beam tip were observed for planar joints and spatial joint, respectively. And RC joint with slab failed with the plastic hinge in the slab and bottom of the beam. The results indicated that hysteretic curves of spatial joints with solid-web steel were plumper than those with hollow-web specimens. The capacity of planar joints was higher than that of space joints, while the opposite was true for energy-dissipation capacity and ductility. The high compression ratio contributed to the increase in capacity and initial stiffness of the joint. The elastic and elastic-plastic story deformation capacity of L-shaped column frame joints satisfied the code requirement. A design formula of joint shear resistance based on the superposition theory and equilibrium plasticity truss model was proposed for engineering application.
{"title":"Seismic behavior and strength of L-shaped steel reinforced concrete column-concrete beam planar and spatial joints","authors":"Zongping Chen, Deyi Xu, Jinjun Xu, Ni Wang","doi":"10.12989/SCS.2021.39.3.337","DOIUrl":"https://doi.org/10.12989/SCS.2021.39.3.337","url":null,"abstract":"The study presented experimental and numerical investigation on the seismic performance of steel reinforced concrete (SRC) L-shaped column- reinforced concrete (RC) beam joints. Various parameters described as steel configuration form, axial compressive ratio, loading angle, and the existence of slab were examined through 4 planar joints and 7 spatial joints. The characteristics of the load-displacement response included the bearing capacity, ductility, story drift ratio, energy-dissipating capacity, and stiffness degradation were analyzed. The results showed that shear failure and flexural failure in the beam tip were observed for planar joints and spatial joint, respectively. And RC joint with slab failed with the plastic hinge in the slab and bottom of the beam. The results indicated that hysteretic curves of spatial joints with solid-web steel were plumper than those with hollow-web specimens. The capacity of planar joints was higher than that of space joints, while the opposite was true for energy-dissipation capacity and ductility. The high compression ratio contributed to the increase in capacity and initial stiffness of the joint. The elastic and elastic-plastic story deformation capacity of L-shaped column frame joints satisfied the code requirement. A design formula of joint shear resistance based on the superposition theory and equilibrium plasticity truss model was proposed for engineering application.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"39 1","pages":"337"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66592091","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.2021.39.4.471
P. G. Asteris, M. Lemonis, Thuy-Anh Nguyen, H. V. Le, B. Pham
In this study, we estimate the ultimate load of rectangular concrete-filled steel tubes (CFST) by developing a novel hybrid predictive model (ANN-BCMO) which is a combination of balancing composite motion optimization (BCMO) - a very new optimization technique and artificial neural network (ANN). For this aim, an experimental database consisting of 422 datasets is used for the development and validation of the ANN-BCMO model. Variables in the database are related with the geometrical characteristics of the structural members, and the mechanical properties of the constituent materials (steel and concrete). Validation of the hybrid ANN-BCMO model is carried out by applying standard statistical criteria such as root mean square error (RMSE), coefficient of determination (R2), and mean absolute error (MAE). In addition, the selection of appropriate values for parameters of the hybrid ANN-BCMO is conducted and its robustness is evaluated and compared with the conventional ANN techniques. The results reveal that the new hybrid ANN-BCMO model is a promising tool for prediction of the ultimate load of rectangular CFST, and prove the effective role of BCMO as a powerful algorithm in optimizing and improving the capability of the ANN predictor.
{"title":"Soft computing-based estimation of ultimate axial load of rectangular concrete-filled steel tubes","authors":"P. G. Asteris, M. Lemonis, Thuy-Anh Nguyen, H. V. Le, B. Pham","doi":"10.12989/SCS.2021.39.4.471","DOIUrl":"https://doi.org/10.12989/SCS.2021.39.4.471","url":null,"abstract":"In this study, we estimate the ultimate load of rectangular concrete-filled steel tubes (CFST) by developing a novel hybrid predictive model (ANN-BCMO) which is a combination of balancing composite motion optimization (BCMO) - a very new optimization technique and artificial neural network (ANN). For this aim, an experimental database consisting of 422 datasets is used for the development and validation of the ANN-BCMO model. Variables in the database are related with the geometrical characteristics of the structural members, and the mechanical properties of the constituent materials (steel and concrete). Validation of the hybrid ANN-BCMO model is carried out by applying standard statistical criteria such as root mean square error (RMSE), coefficient of determination (R2), and mean absolute error (MAE). In addition, the selection of appropriate values for parameters of the hybrid ANN-BCMO is conducted and its robustness is evaluated and compared with the conventional ANN techniques. The results reveal that the new hybrid ANN-BCMO model is a promising tool for prediction of the ultimate load of rectangular CFST, and prove the effective role of BCMO as a powerful algorithm in optimizing and improving the capability of the ANN predictor.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"39 1","pages":"471"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66592703","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.2021.39.6.765
Sadra Shahsavar, M. Fakoor, F. Berto
In this paper, a fracture criterion for predicting the failure of the cracked composite specimens under mixed mode I/II loading is provided. Various tests performed on composite components reveal that cracks always grow along the fibers in the isotropic media. Using a new material model called reinforcement isotropic solid (RIS) concept, it is possible to extend the isotropic mixed mode fracture criteria into composite materials. In the proposed criterion, maximum shear stress (MSS) theory which is widely used for failure investigation of un-cracked isotropic materials will be extended to composite materials in combination with RIS concept. In the present study, cracks are oriented along the fibers in the isotropic material. It is assumed that at the onset of fracture, crack growth will be in a path where the shear stress has the highest value according to the MSS criterion. Investigating the results of this criterion and comparing with the available experimental data, it is shown that, both the crack propagation path and the moment of crack growth are well predicted. Available mixed mode I/II fracture data of various wood species are used to evaluate and verify the theoretical results.
{"title":"Mixed mode I/II fracture criterion to anticipate cracked composite materials based on a reinforced kinked crack along maximum shear stress path","authors":"Sadra Shahsavar, M. Fakoor, F. Berto","doi":"10.12989/SCS.2021.39.6.765","DOIUrl":"https://doi.org/10.12989/SCS.2021.39.6.765","url":null,"abstract":"In this paper, a fracture criterion for predicting the failure of the cracked composite specimens under mixed mode I/II loading is provided. Various tests performed on composite components reveal that cracks always grow along the fibers in the isotropic media. Using a new material model called reinforcement isotropic solid (RIS) concept, it is possible to extend the isotropic mixed mode fracture criteria into composite materials. In the proposed criterion, maximum shear stress (MSS) theory which is widely used for failure investigation of un-cracked isotropic materials will be extended to composite materials in combination with RIS concept. In the present study, cracks are oriented along the fibers in the isotropic material. It is assumed that at the onset of fracture, crack growth will be in a path where the shear stress has the highest value according to the MSS criterion. Investigating the results of this criterion and comparing with the available experimental data, it is shown that, both the crack propagation path and the moment of crack growth are well predicted. Available mixed mode I/II fracture data of various wood species are used to evaluate and verify the theoretical results.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"39 1","pages":"765"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66593540","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.2021.40.5.733
S. Vijayanand, M. Anbarasu
This paper presents the parametric study on the strength and behaviour of CFS closed built-up battened columns. The CFS closed built-up battened column consists of two lipped channels placed face-to-face with a uniform spacing of battens. Finite element models are validated with the results of the test specimens available in the thesis of the first author. The parametric study on 176 cold-formed steel built-up column sections is extended by using the validated finite element modeling covering a wide range of global column slenderness, plate slenderness and yield stress. The numerical results from the parametric study are compared with the design strengths calculated by the European specifications (EN1993-1-3:2006) and AISI Specifications (AISI S100:2016). The comparison of parametric results with the design strength predictions has indicated the design guidelines of the specifications need improvement. The design strength predictions of the specifications are also assessed by conducting the reliability analysis. Therefore, the exiting design rules are modified to improve the accuracy of the design strength predictions for the CFS closed built-up battened columns subjected to the axial compression. Furthermore, the reliability of the proposed methods is confirmed by means of reliability analysis.
{"title":"Parametric study and Improved design guidelines of CFS battened built-up columns","authors":"S. Vijayanand, M. Anbarasu","doi":"10.12989/SCS.2021.40.5.733","DOIUrl":"https://doi.org/10.12989/SCS.2021.40.5.733","url":null,"abstract":"This paper presents the parametric study on the strength and behaviour of CFS closed built-up battened columns. The CFS closed built-up battened column consists of two lipped channels placed face-to-face with a uniform spacing of battens. Finite element models are validated with the results of the test specimens available in the thesis of the first author. The parametric study on 176 cold-formed steel built-up column sections is extended by using the validated finite element modeling covering a wide range of global column slenderness, plate slenderness and yield stress. The numerical results from the parametric study are compared with the design strengths calculated by the European specifications (EN1993-1-3:2006) and AISI Specifications (AISI S100:2016). The comparison of parametric results with the design strength predictions has indicated the design guidelines of the specifications need improvement. The design strength predictions of the specifications are also assessed by conducting the reliability analysis. Therefore, the exiting design rules are modified to improve the accuracy of the design strength predictions for the CFS closed built-up battened columns subjected to the axial compression. Furthermore, the reliability of the proposed methods is confirmed by means of reliability analysis.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"40 1","pages":"733"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66596484","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.2021.41.2.223
Hnin Wai Hlaing, P. Panedpojaman
The deflection of composite (cellular) beams is important for serviceability purposes. However, the available methods to predict the deflection are inaccurate. This research aims to propose a method for predicting the deflection with improved accuracy. The proposed deflection consists of contributions from overall flexural behavior and Vierendeel bending. In addition to the slip action, a reduction factor for computing the effective moment of inertia is investigated and used to compute the flexural deflection. The Vierendeel deformation was determined based on shear deflection of a virtual cantilever beam. No local composite action is conservatively assumed in the cantilever beam. Over 700 three-dimensional finite element (FE) models were simulated to investigate the reduction factor and limitations of the proposed method. The FE model was validated against 13 experimental load-deflection curves from the literature. The proposed method is suitable for predicting the deflection of composite cellular beams having the spacing ratio 1.35 or higher and the span ratio higher than 5. For such cases, the deflection estimate is from 0.90 to 1.05 times the FE deflection. The web-post deformation and the global shear deflection affect the prediction accuracy. In comparison to other methods, the proposed method is more accurate in predicting the deflection.
{"title":"Deflection of composite cellular beams","authors":"Hnin Wai Hlaing, P. Panedpojaman","doi":"10.12989/SCS.2021.41.2.223","DOIUrl":"https://doi.org/10.12989/SCS.2021.41.2.223","url":null,"abstract":"The deflection of composite (cellular) beams is important for serviceability purposes. However, the available methods to predict the deflection are inaccurate. This research aims to propose a method for predicting the deflection with improved accuracy. The proposed deflection consists of contributions from overall flexural behavior and Vierendeel bending. In addition to the slip action, a reduction factor for computing the effective moment of inertia is investigated and used to compute the flexural deflection. The Vierendeel deformation was determined based on shear deflection of a virtual cantilever beam. No local composite action is conservatively assumed in the cantilever beam. Over 700 three-dimensional finite element (FE) models were simulated to investigate the reduction factor and limitations of the proposed method. The FE model was validated against 13 experimental load-deflection curves from the literature. The proposed method is suitable for predicting the deflection of composite cellular beams having the spacing ratio 1.35 or higher and the span ratio higher than 5. For such cases, the deflection estimate is from 0.90 to 1.05 times the FE deflection. The web-post deformation and the global shear deflection affect the prediction accuracy. In comparison to other methods, the proposed method is more accurate in predicting the deflection.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"41 1","pages":"223"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66597153","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.2021.41.2.237
Guoqiang Zhang, W. Feng, M. Shao, F. Ma
Safety monitoring and stability analysis of high slopes are essential for construction of concrete dam in precipitous gorges or mountainous areas. The estimate of slope stability is a difficult engineering shortcoming with a number of variables. Thereafter, a hybrid model of Support Vector Regression (SVR) and Teaching–learning-based optimization technique (TLBO) is proposed to develop the predicting function. TLBO was used in obtaining the best SRV factors to improve the prediction accuracy. Few essential factors, such as the installation height of instruments, classification of rock masses, modulus of elasticity, the complete measuring time cycle, the excavation height of slope, the start measuring time, and the actual excavation height after measurement are considered as the input parameter, but the slope displacement is regarded as output. The outcomes showed SRV-TLBO a reliable hybrid accurate prediction of slope stability, then it was effectively used to the left abutment slope of Jinping I hydropower station located in Yalongjiang concrete dam reservoir as a novel method for this purpose.
{"title":"Reservoir bank slope stability prediction model based on BP neural network","authors":"Guoqiang Zhang, W. Feng, M. Shao, F. Ma","doi":"10.12989/SCS.2021.41.2.237","DOIUrl":"https://doi.org/10.12989/SCS.2021.41.2.237","url":null,"abstract":"Safety monitoring and stability analysis of high slopes are essential for construction of concrete dam in precipitous gorges or mountainous areas. The estimate of slope stability is a difficult engineering shortcoming with a number of variables. Thereafter, a hybrid model of Support Vector Regression (SVR) and Teaching–learning-based optimization technique (TLBO) is proposed to develop the predicting function. TLBO was used in obtaining the best SRV factors to improve the prediction accuracy. Few essential factors, such as the installation height of instruments, classification of rock masses, modulus of elasticity, the complete measuring time cycle, the excavation height of slope, the start measuring time, and the actual excavation height after measurement are considered as the input parameter, but the slope displacement is regarded as output. The outcomes showed SRV-TLBO a reliable hybrid accurate prediction of slope stability, then it was effectively used to the left abutment slope of Jinping I hydropower station located in Yalongjiang concrete dam reservoir as a novel method for this purpose.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"41 1","pages":"237"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66597893","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.2021.41.2.249
M. Wei, Xie Jianhe, Weicai Liu
To meet the demands of the sustainable development of construction, the combination of precast structures and recycled aggregate concrete made from construction and demolition waste is being promoted as a promising green construction technology. In this study, a new prefabricated member, a buckling-restrained steel plate shear wall with a cover plate made of recycled aggregate concrete (PBRW), was developed and experimentally studied. Eight specimens were tested to study the effect of the cover plate with different recycled aggregate substitution ratios and various bolt arrangements on the seismic behavior of this shear wall system. Based on the high-order buckling in the inner steel plate, a theoretical method was proposed to predict the shear resistance of PBRWs. The test results indicated that the PBRWs exhibited high shear strength, an adequate initial stiffness, a favorable energy absorption capacity, and a stable hysteresis curve. A full replacement of recycled aggregate with natural aggregate had almost no adverse impact on the seismic behavior of the PBRWs. The wall with an insufficient number of bolts (bolt arrangement of 3x2) imposed weaker lateral constraints on the inner plate, resulting in a reduction in the seismic behavior.
{"title":"Buckling-restrained steel plate shear walls using recycled aggregate concrete: Experimental and analytical study","authors":"M. Wei, Xie Jianhe, Weicai Liu","doi":"10.12989/SCS.2021.41.2.249","DOIUrl":"https://doi.org/10.12989/SCS.2021.41.2.249","url":null,"abstract":"To meet the demands of the sustainable development of construction, the combination of precast structures and recycled aggregate concrete made from construction and demolition waste is being promoted as a promising green construction technology. In this study, a new prefabricated member, a buckling-restrained steel plate shear wall with a cover plate made of recycled aggregate concrete (PBRW), was developed and experimentally studied. Eight specimens were tested to study the effect of the cover plate with different recycled aggregate substitution ratios and various bolt arrangements on the seismic behavior of this shear wall system. Based on the high-order buckling in the inner steel plate, a theoretical method was proposed to predict the shear resistance of PBRWs. The test results indicated that the PBRWs exhibited high shear strength, an adequate initial stiffness, a favorable energy absorption capacity, and a stable hysteresis curve. A full replacement of recycled aggregate with natural aggregate had almost no adverse impact on the seismic behavior of the PBRWs. The wall with an insufficient number of bolts (bolt arrangement of 3x2) imposed weaker lateral constraints on the inner plate, resulting in a reduction in the seismic behavior.","PeriodicalId":51177,"journal":{"name":"Steel and Composite Structures","volume":"41 1","pages":"249"},"PeriodicalIF":4.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66597950","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}
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