Pub Date : 2024-11-06DOI: 10.1016/j.jcsr.2024.109133
Mingming Wang , Danni Liu , Yichen Lu , Qiang Yang , Danqing Song , Xiaoli Liu
Metal roof systems have been widely used in various landmark buildings. The effect of the temperature of a large-span metal roof system under solar radiation is significant. As the latest roof form, the continuous welded stainless steel roof (CWSSR) system shows many unknown behaviors under the action of temperature. The purpose of this work is to analyse the temperature field and temperature effect of the CWSSR system under solar radiation and to select the appropriate support layouts to reduce the temperature effect of the CWSSR system. First, an experimental study on the temperature field of the CWSSR system was carried out. Finite element analysis of the temperature field distribution was then performed, and the validity of the finite element method was verified by comparing the experimental results. Finally, the influence of different support layouts on the temperature effect of the CWSSR system was researched. The results show that there is an obvious nonuniform distribution of the temperature field and temperature effect of the CWSSR system under solar radiation. The maximum temperature difference between the roof panel and the ambient temperature is 39.4 °C. By using arrangements of cross-support and segmented support, the stresses of the roof panel and support can be effectively reduced, and the maximum reductions are 14.4 % and 38.9 %, respectively. The investigation results contribute the most to the safe design of metal roof systems and are expected to provide guidelines for future applications of the CWSSR system.
{"title":"Investigation into the nonuniform temperature effect of a large-span stainless steel roof system under solar radiation","authors":"Mingming Wang , Danni Liu , Yichen Lu , Qiang Yang , Danqing Song , Xiaoli Liu","doi":"10.1016/j.jcsr.2024.109133","DOIUrl":"10.1016/j.jcsr.2024.109133","url":null,"abstract":"<div><div>Metal roof systems have been widely used in various landmark buildings. The effect of the temperature of a large-span metal roof system under solar radiation is significant. As the latest roof form, the continuous welded stainless steel roof (CWSSR) system shows many unknown behaviors under the action of temperature. The purpose of this work is to analyse the temperature field and temperature effect of the CWSSR system under solar radiation and to select the appropriate support layouts to reduce the temperature effect of the CWSSR system. First, an experimental study on the temperature field of the CWSSR system was carried out. Finite element analysis of the temperature field distribution was then performed, and the validity of the finite element method was verified by comparing the experimental results. Finally, the influence of different support layouts on the temperature effect of the CWSSR system was researched. The results show that there is an obvious nonuniform distribution of the temperature field and temperature effect of the CWSSR system under solar radiation. The maximum temperature difference between the roof panel and the ambient temperature is 39.4 °C. By using arrangements of cross-support and segmented support, the stresses of the roof panel and support can be effectively reduced, and the maximum reductions are 14.4 % and 38.9 %, respectively. The investigation results contribute the most to the safe design of metal roof systems and are expected to provide guidelines for future applications of the CWSSR system.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109133"},"PeriodicalIF":4.0,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-06DOI: 10.1016/j.jcsr.2024.109132
Shuangshuang Jin , Shengchao Yang , Xingming Zhang
The buckling-restrained steel plate shear wall with inclined slots (called Slotted-SPSW), composed of slotted steel plate, frame beams and columns, and out-of-plane constrained concrete panels. Premature failure of boundary frames may lead to insufficient performance of the Slotted-SPSW. To understand the interaction between the slotted steel plate and the boundary frame, the theoretical formula for calculating ultimate load-bearing capacity of the novel Slotted-SPSW is initially provided, and then internal forces in boundary columns are derived through theoretical analysis. Subsequently, a quasi-static experiment on a scale model with a ratio of 1:3 is conducted to examine the mechanical behavior and failure modes of the Slotted-SPSW under lateral forces. Finally, a comparison between the finite element simulation results for the frame columns and slotted steel plate and the experimental results is presented, verifying the accuracy of the theoretical formulas and finite element simulations. The research findings demonstrate that the novel Slotted-SPSW possesses exceptional load-bearing capacity, energy dissipation ability and ductility.
{"title":"Theoretical and experimental study on the interaction between slotted steel plate shear wall and boundary frame","authors":"Shuangshuang Jin , Shengchao Yang , Xingming Zhang","doi":"10.1016/j.jcsr.2024.109132","DOIUrl":"10.1016/j.jcsr.2024.109132","url":null,"abstract":"<div><div>The buckling-restrained steel plate shear wall with inclined slots (called Slotted-SPSW), composed of slotted steel plate, frame beams and columns, and out-of-plane constrained concrete panels. Premature failure of boundary frames may lead to insufficient performance of the Slotted-SPSW. To understand the interaction between the slotted steel plate and the boundary frame, the theoretical formula for calculating ultimate load-bearing capacity of the novel Slotted-SPSW is initially provided, and then internal forces in boundary columns are derived through theoretical analysis. Subsequently, a quasi-static experiment on a scale model with a ratio of 1:3 is conducted to examine the mechanical behavior and failure modes of the Slotted-SPSW under lateral forces. Finally, a comparison between the finite element simulation results for the frame columns and slotted steel plate and the experimental results is presented, verifying the accuracy of the theoretical formulas and finite element simulations. The research findings demonstrate that the novel Slotted-SPSW possesses exceptional load-bearing capacity, energy dissipation ability and ductility.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109132"},"PeriodicalIF":4.0,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-05DOI: 10.1016/j.jcsr.2024.109125
Dazhe Feng , Zhanzhong Yin , Shaobo Xu
The stability and capacity of thin-walled steel columns can be considerably upgraded by filling concrete into hollow spaces surrounded by cold-formed lipped channel (CLC) and external battens. However, there is limited experimental data available, especially for the axial compression behavior of concrete-filled CLC partially encased composite (PEC) columns. This paper aims to investigate the compressive behavior of CLC-PEC short columns and presents an analytical model for predicting the axial capacity of the column. The study explores the influences of cross-sectional dimensions and external batten plate configurations on the compressive performance of CLC-PEC columns through axial compression tests conducted on 12 short column specimens. The results indicate that the failure modes of the specimens involve localized concrete spalling on the exposed side at the lower part of the column, along with a elephant foot-shaped buckling of the cold-formed steel lipped channel. The damage surface of the confined concrete was obtained by circumferential cutting of the buckling location. The findings highlight the significant influence of the character of the CLC section on the ineffectively confined area at the failure surface, with a dumbbell-shaped effective confinement zone revealing the presence of a highly confined area. Based on the calibrated failure surfaces, a numerical model-based study of the axial stress distribution in the concrete core was then carried out to estimate the confinement effect of the columns under peak loading. The study employed multiple regression analysis to quantify the area ratio of the confined zone to the concrete core based on finite element analysis (FEA) results from 143 CLC-PEC columns. The proposed model was evaluated against test results and found to be more reliable than axial compression loads based on the superposition strength method. The proposed axial capacity of short columns takes into account the slenderness ratio of each member.
{"title":"Axial compressive behavior and capacity prediction of concrete-filled cold-formed lipped channel PEC stub columns","authors":"Dazhe Feng , Zhanzhong Yin , Shaobo Xu","doi":"10.1016/j.jcsr.2024.109125","DOIUrl":"10.1016/j.jcsr.2024.109125","url":null,"abstract":"<div><div>The stability and capacity of thin-walled steel columns can be considerably upgraded by filling concrete into hollow spaces surrounded by cold-formed lipped channel (CLC) and external battens. However, there is limited experimental data available, especially for the axial compression behavior of concrete-filled CLC partially encased composite (PEC) columns. This paper aims to investigate the compressive behavior of CLC-PEC short columns and presents an analytical model for predicting the axial capacity of the column. The study explores the influences of cross-sectional dimensions and external batten plate configurations on the compressive performance of CLC-PEC columns through axial compression tests conducted on 12 short column specimens. The results indicate that the failure modes of the specimens involve localized concrete spalling on the exposed side at the lower part of the column, along with a elephant foot-shaped buckling of the cold-formed steel lipped channel. The damage surface of the confined concrete was obtained by circumferential cutting of the buckling location. The findings highlight the significant influence of the character of the CLC section on the ineffectively confined area at the failure surface, with a dumbbell-shaped effective confinement zone revealing the presence of a highly confined area. Based on the calibrated failure surfaces, a numerical model-based study of the axial stress distribution in the concrete core was then carried out to estimate the confinement effect of the columns under peak loading. The study employed multiple regression analysis to quantify the area ratio of the confined zone to the concrete core based on finite element analysis (FEA) results from 143 CLC-PEC columns. The proposed model was evaluated against test results and found to be more reliable than axial compression loads based on the superposition strength method. The proposed axial capacity of short columns takes into account the slenderness ratio of each member.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109125"},"PeriodicalIF":4.0,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-05DOI: 10.1016/j.jcsr.2024.109129
Shujun Hu , Shangwen Liu , Sizhi Zeng , Bo Zhang , Zhenhuan Xu
This paper introduces an innovative self-centering shear link (SC-SL) that combines the self-centering SMA braces (SCB) and very short shear link with shear slotted bolted connection (VSSL-SSBC), commonly used in the eccentrically braced frames (EBFs). Four SC-SL specimens differing in bolt pretension and loading displacement were designed to investigate the seismic performance, enabling the acquisition of hysteresis curves, skeletal curves, secant stiffness curves and energy dissipation capacity of the SC-SL. Additionally, extensive parametric studies, validated by finite element (FE) modeling technique, were conducted to investigate the main influencing parameters of the SC-SL. Test results indicated that the VSSL in the VSSL-SSBC remained in the slip stage without any relative deformation and yielding during the slip stage, whereas slip deformation, web yield, and web and flange buckling occurred during the non-slip stage. The deformation and stress of the SMA wires in the SCB increased gradually and remained in tension throughout the loading process. Hysteresis curves of the SC-SL exhibited elastic and elastic-plastic during the slip stage, and elastic, elastic-plastic, and strengthening stages during the non-slip stage. In addition, enlarging the SMA areas can enhance the bearing capacity and reduce the residual deformation of SC-SL during both slip and non-slip stage. Finally, the simplified mechanical models of SC-SL were proposed and validated, indicated that the proposed equation was in good agreement with the FE simulation results, with a maximum error of 8.99 % and 4.86 % during the slip and non-slip stage, respectively.
本文介绍了一种创新的自定心剪力连杆（SC-SL），它结合了偏心支撑框架（EBF）中常用的自定心 SMA 支撑（SCB）和带剪力槽螺栓连接的超短剪力连杆（VSSL-SSBC）。为了研究 SC-SL 的抗震性能，设计了四种螺栓预拉力和加载位移不同的 SC-SL 试样，从而获得了 SC-SL 的滞后曲线、骨架曲线、正弦刚度曲线和耗能能力。此外，还通过有限元（FE）建模技术进行了广泛的参数研究，以调查 SC-SL 的主要影响参数。试验结果表明，VSSL-SSBC 中的 VSSL 始终处于滑移阶段，在滑移阶段没有发生任何相对变形和屈服，而在非滑移阶段发生了滑移变形、腹板屈服以及腹板和翼板屈曲。在整个加载过程中，SCB 中的 SMA 线的变形和应力逐渐增加，并保持在拉伸状态。SC-SL 的滞后曲线在滑移阶段表现为弹性和弹塑性，在非滑移阶段表现为弹性、弹塑性和强化阶段。此外，扩大 SMA 面积可提高 SC-SL 的承载能力，并减少其在滑移和非滑移阶段的残余变形。最后，提出并验证了 SC-SL 的简化力学模型，结果表明所提出的方程与 FE 仿真结果吻合良好，在滑移和非滑移阶段的最大误差分别为 8.99 % 和 4.86 %。
{"title":"Investigating seismic performance of a novel self-centering shear link in EBF utilizing experimental and numerical simulation","authors":"Shujun Hu , Shangwen Liu , Sizhi Zeng , Bo Zhang , Zhenhuan Xu","doi":"10.1016/j.jcsr.2024.109129","DOIUrl":"10.1016/j.jcsr.2024.109129","url":null,"abstract":"<div><div>This paper introduces an innovative self-centering shear link (SC-SL) that combines the self-centering SMA braces (SCB) and very short shear link with shear slotted bolted connection (VSSL-SSBC), commonly used in the eccentrically braced frames (EBFs). Four SC-SL specimens differing in bolt pretension and loading displacement were designed to investigate the seismic performance, enabling the acquisition of hysteresis curves, skeletal curves, secant stiffness curves and energy dissipation capacity of the SC-SL. Additionally, extensive parametric studies, validated by finite element (FE) modeling technique, were conducted to investigate the main influencing parameters of the SC-SL. Test results indicated that the VSSL in the VSSL-SSBC remained in the slip stage without any relative deformation and yielding during the slip stage, whereas slip deformation, web yield, and web and flange buckling occurred during the non-slip stage. The deformation and stress of the SMA wires in the SCB increased gradually and remained in tension throughout the loading process. Hysteresis curves of the SC-SL exhibited elastic and elastic-plastic during the slip stage, and elastic, elastic-plastic, and strengthening stages during the non-slip stage. In addition, enlarging the SMA areas can enhance the bearing capacity and reduce the residual deformation of SC-SL during both slip and non-slip stage. Finally, the simplified mechanical models of SC-SL were proposed and validated, indicated that the proposed equation was in good agreement with the FE simulation results, with a maximum error of 8.99 % and 4.86 % during the slip and non-slip stage, respectively.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109129"},"PeriodicalIF":4.0,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-05DOI: 10.1016/j.jcsr.2024.109112
Christian Dänekas , Jan Schubnell , Johannes Krautheimer , Matthias Jung , Elyas Ghafoori , Peter Schaumann
This paper addresses the challenge of precise determination of weld toe radius and flank angle in welded joints. Despite the importance of these parameters for fatigue strength, existing research has not provided clear computational methods for their accurate evaluation. To address this research gap, various evaluation algorithms were developed and applied to both artificially generated profiles of butt-welded and fillet-welded joints and real digital scan data of a reference specimen. The study derives initial recommendations for data quality and the selection of evaluation methods based on weld seam geometry and point spacing. These recommendations consider the demonstrated areas of validity and limitations. The results show that a least squares approach offers the greatest potential to accurately determine weld toe radii. Additionally, the flank angle can be well determined using the gradient of the weld seam profile. The results improve the understanding in assessment of weld seam geometries, enabling automated and precise weld quality inspection in the future. This study may contribute in the future derivation of normative and harmonization regulations for the determination of weld toe parameters.
{"title":"Algorithms for determination of weld toe radius and weld toe angle in welded joints","authors":"Christian Dänekas , Jan Schubnell , Johannes Krautheimer , Matthias Jung , Elyas Ghafoori , Peter Schaumann","doi":"10.1016/j.jcsr.2024.109112","DOIUrl":"10.1016/j.jcsr.2024.109112","url":null,"abstract":"<div><div>This paper addresses the challenge of precise determination of weld toe radius and flank angle in welded joints. Despite the importance of these parameters for fatigue strength, existing research has not provided clear computational methods for their accurate evaluation. To address this research gap, various evaluation algorithms were developed and applied to both artificially generated profiles of butt-welded and fillet-welded joints and real digital scan data of a reference specimen. The study derives initial recommendations for data quality and the selection of evaluation methods based on weld seam geometry and point spacing. These recommendations consider the demonstrated areas of validity and limitations. The results show that a least squares approach offers the greatest potential to accurately determine weld toe radii. Additionally, the flank angle can be well determined using the gradient of the weld seam profile. The results improve the understanding in assessment of weld seam geometries, enabling automated and precise weld quality inspection in the future. This study may contribute in the future derivation of normative and harmonization regulations for the determination of weld toe parameters.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109112"},"PeriodicalIF":4.0,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-05DOI: 10.1016/j.jcsr.2024.109122
Wei Xian , Zhi-Meng Wang , Wensu Chen , Wen-Da Wang , Rui Wang
Very limited studies have been conducted to investigate the influences of different internal configurations and the size effect on the impact responses of SRCFST members. In this study, numerical simulations are conducted by using ABAQUS. The numerical model of SRCFST members under lateral impact directly incorporates material damage, strain rate effect and steel fracture, and the model is verified against available impact testing data. Following model verification, the impact behaviors of SRCFST members with four commonly used internal configurations of steel sections are compared and discussed. It is found that the damage modes of SRCFST members are largely unaffected by internal configurations. These internal configurations minimally affect energy absorption capacity, with a maximum difference of only 2.04 %. SRCFST specimen with inner steel tube (SRCFST-T1) exhibits the best impact resistance performance among four types by showing its ability to sustain the highest impact force plateau, the least mid-span deformation and the largest bending moment. Moreover, the size effects on dynamic responses are also investigated. The results show that the key indicators (e.g., the peak impact force, plateau impact force, impact duration, maximum mid-span displacement, and energy absorption) closely align with the standard lines, displaying a maximum deviation of less than 10 %. The traditional similarity law is verified in predicting the impact responses using the scaling factor. Finally, an improved single-degree-of-freedom (SDOF) analytical model is formulated for predicting the displacement responses of SRCFST members under drop weight impact, and it gives an accurate prediction of the displacement response.
{"title":"Analytical investigations on dynamic responses of SRCFST members under lateral impact loads","authors":"Wei Xian , Zhi-Meng Wang , Wensu Chen , Wen-Da Wang , Rui Wang","doi":"10.1016/j.jcsr.2024.109122","DOIUrl":"10.1016/j.jcsr.2024.109122","url":null,"abstract":"<div><div>Very limited studies have been conducted to investigate the influences of different internal configurations and the size effect on the impact responses of SRCFST members. In this study, numerical simulations are conducted by using ABAQUS. The numerical model of SRCFST members under lateral impact directly incorporates material damage, strain rate effect and steel fracture, and the model is verified against available impact testing data. Following model verification, the impact behaviors of SRCFST members with four commonly used internal configurations of steel sections are compared and discussed. It is found that the damage modes of SRCFST members are largely unaffected by internal configurations. These internal configurations minimally affect energy absorption capacity, with a maximum difference of only 2.04 %. SRCFST specimen with inner steel tube (SRCFST-T1) exhibits the best impact resistance performance among four types by showing its ability to sustain the highest impact force plateau, the least mid-span deformation and the largest bending moment. Moreover, the size effects on dynamic responses are also investigated. The results show that the key indicators (e.g., the peak impact force, plateau impact force, impact duration, maximum mid-span displacement, and energy absorption) closely align with the standard lines, displaying a maximum deviation of less than 10 %. The traditional similarity law is verified in predicting the impact responses using the scaling factor. Finally, an improved single-degree-of-freedom (SDOF) analytical model is formulated for predicting the displacement responses of SRCFST members under drop weight impact, and it gives an accurate prediction of the displacement response.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109122"},"PeriodicalIF":4.0,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-05DOI: 10.1016/j.jcsr.2024.109124
De-Bin Wang , Si-han Wang , Zhi-Guo Sun , Wen-Ming Wang
A novel torsional steel tube damper with deformation amplification function (DATSTD) to address the issue that traditional metallic dampers cannot sufficiently dissipate energy under small deformation was proposed. The basic structure and working mechanism of the DATSTD were described. A theoretical restoring force model was derived, together with an amplification formula for the deformation and load-bearing capacity of the DATSTD. The seismic performance of the DATSTD with varying initial amplification angles was investigated by low-cycle cyclic loading test, and the energy dissipation and failure mechanism of the DATSTD were studied. A robust finite element model for the DATSTD was developed using the ABAQUS software, and the effect of the rotating plate length on the mechanical properties of the DATSTD was studied in detail. The test results show that the hysteresis curve of the damper is smooth and full, exhibits certain asymmetric features, and maintains a stable and efficient energy dissipation capacity. By reducing the initial amplification angle, the plastic deformation of the energy-dissipation steel tube progresses more extensively, the equivalent viscous damping coefficient rapidly increases to approximately 50 %, and the yield load, maximum load, and initial stiffness of the damper all increase significantly. While the asymmetry of the hysteretic curve is also slightly enhanced. The theoretical restoring force model and the finite element model could predict the performance of the DATSTD well. With reduction of the rotating plate length, the influence of the initial amplification angle change on the energy dissipation and load-bearing capacity of the damper would be increased. The maximum tensile-to-compressive load ratio of the damper would be increased and the asymmetry of the hysteretic curve becomes more pronounced as decreasing of the of the rotating plate length.
{"title":"Experimental and analytical investigation on the behavior of deformation-amplified torsional steel-tube dampers","authors":"De-Bin Wang , Si-han Wang , Zhi-Guo Sun , Wen-Ming Wang","doi":"10.1016/j.jcsr.2024.109124","DOIUrl":"10.1016/j.jcsr.2024.109124","url":null,"abstract":"<div><div>A novel torsional steel tube damper with deformation amplification function (DATSTD) to address the issue that traditional metallic dampers cannot sufficiently dissipate energy under small deformation was proposed. The basic structure and working mechanism of the DATSTD were described. A theoretical restoring force model was derived, together with an amplification formula for the deformation and load-bearing capacity of the DATSTD. The seismic performance of the DATSTD with varying initial amplification angles was investigated by low-cycle cyclic loading test, and the energy dissipation and failure mechanism of the DATSTD were studied. A robust finite element model for the DATSTD was developed using the ABAQUS software, and the effect of the rotating plate length on the mechanical properties of the DATSTD was studied in detail. The test results show that the hysteresis curve of the damper is smooth and full, exhibits certain asymmetric features, and maintains a stable and efficient energy dissipation capacity. By reducing the initial amplification angle, the plastic deformation of the energy-dissipation steel tube progresses more extensively, the equivalent viscous damping coefficient rapidly increases to approximately 50 %, and the yield load, maximum load, and initial stiffness of the damper all increase significantly. While the asymmetry of the hysteretic curve is also slightly enhanced. The theoretical restoring force model and the finite element model could predict the performance of the DATSTD well. With reduction of the rotating plate length, the influence of the initial amplification angle change on the energy dissipation and load-bearing capacity of the damper would be increased. The maximum tensile-to-compressive load ratio of the damper would be increased and the asymmetry of the hysteretic curve becomes more pronounced as decreasing of the of the rotating plate length.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109124"},"PeriodicalIF":4.0,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-05DOI: 10.1016/j.jcsr.2024.109113
Quang-Viet Vu , Dai-Nhan Le , Tuan-Dung Pham , Wei Gao , Sawekchai Tangaramvong
This paper proposes a novel procedure for prediction of both load-displacement curve and load-carrying capacity of concrete-filled double-skin steel tube (CFDST) columns under uniaxial compression by using convolutional neural network (CNN)-based regression and Nelder-Mead methods. Firstly, hybrid databases collected from experiments in literature and generated from finite element analyses are employed to build the proposed CNN-based model. The accuracy of the proposed model is described through a comparison between predictive results of the proposed model and unseen data. Two machine learning models, including eXtreme Gradient Boosting and Multilayer Perceptron, are adopted for comparison. It can be observed that the CNN-based model provides the most accurate predictions for both the load-displacement curve and axial compression capacity of CFDST columns in both experimental and numerical databases. An efficient procedure is developed to calibrate the preliminary load-displacement curve estimated by the CNN-based model, and to notably enhance its smoothness and performance. Adjusted formulae (based on well-known equations) are obtained for predicting the load-displacement curve of CFDST columns. The hyperparameters of these formulae are optimized using the Nelder-Mead method. It is indicated that the adjusted load-displacement curves obtained from the proposed procedure outperform the preliminary curves estimated by the CNN-based model. A sensitivity analysis was conducted to investigate the model's performance in predicting the load-displacement curves of CFDST columns with variations of input variables within stochastic environments. Finally, a cloud-based graphical user interface is developed to provide a convenient tool for users to predict axial load-displacement responses of CFDST columns without prior programming knowledge.
{"title":"An efficient procedure for prediction of the load-displacement curve of CFDST columns","authors":"Quang-Viet Vu , Dai-Nhan Le , Tuan-Dung Pham , Wei Gao , Sawekchai Tangaramvong","doi":"10.1016/j.jcsr.2024.109113","DOIUrl":"10.1016/j.jcsr.2024.109113","url":null,"abstract":"<div><div>This paper proposes a novel procedure for prediction of both load-displacement curve and load-carrying capacity of concrete-filled double-skin steel tube (CFDST) columns under uniaxial compression by using convolutional neural network (CNN)-based regression and Nelder-Mead methods. Firstly, hybrid databases collected from experiments in literature and generated from finite element analyses are employed to build the proposed CNN-based model. The accuracy of the proposed model is described through a comparison between predictive results of the proposed model and unseen data. Two machine learning models, including eXtreme Gradient Boosting and Multilayer Perceptron, are adopted for comparison. It can be observed that the CNN-based model provides the most accurate predictions for both the load-displacement curve and axial compression capacity of CFDST columns in both experimental and numerical databases. An efficient procedure is developed to calibrate the preliminary load-displacement curve estimated by the CNN-based model, and to notably enhance its smoothness and performance. Adjusted formulae (based on well-known equations) are obtained for predicting the load-displacement curve of CFDST columns. The hyperparameters of these formulae are optimized using the Nelder-Mead method. It is indicated that the adjusted load-displacement curves obtained from the proposed procedure outperform the preliminary curves estimated by the CNN-based model. A sensitivity analysis was conducted to investigate the model's performance in predicting the load-displacement curves of CFDST columns with variations of input variables within stochastic environments. Finally, a cloud-based graphical user interface is developed to provide a convenient tool for users to predict axial load-displacement responses of CFDST columns without prior programming knowledge.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109113"},"PeriodicalIF":4.0,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-05DOI: 10.1016/j.jcsr.2024.109131
Chao Hu , Rui Cheng , Yuhang Wang , Meilan Gong , Jichun Liu
The special-shaped concrete-filled steel tube (CFST) structure has attracted considerable scholarly interest in recent years. However, limited attention has been given to research on multi-cell T-shaped CFST (MT-CFST) column, resulting in a lack of uniformity in calculation methods. This paper presents an improved MT-CFST column composed of three rectangular steel tubes, a steel plate, and concrete. This design ensures that welds avoid cold bending zones in steel tubes, thereby enhancing quality of welds. In practical engineering applications, columns often experience biaxial eccentric loads. A biaxial eccentric compression test was conducted on fifteen MT-CFST specimens. This study investigated the influence of eccentricity, eccentric angle, and web height on performance of MT-CFST column. The experimental results revealed a similar failure mode among specimens: prior to peak load, minor bending deformation was observed. For specimens T56.6–60-45° and T40–90-180°, the smaller width-to-thickness ratio of steel plates on compressed side prevented local buckling. For other specimens, slight local buckling on compressed side near mid-span section was observed. After peak load, local buckling progressively intensified, primarily due to substantial bending deformation. The failure of specimens was attributed to local buckling and overall bending deformation. For eccentricity greater than 20 mm, the bearing capacity and elastic-plastic stiffness of specimens exhibited an increasing trend followed by a decreasing trend with the increase in eccentric angle at the same eccentricity, with the peaks occurring at around 90°. Specimens with the compressed side located at flange demonstrated higher bearing capacity and elastic-plastic stiffness. Additionally, FE models have been established to simulate the bidirectional eccentric behavior. A simplified method for calculating flexural capacity was developed, grounded in stress analysis of section at ultimate conditions. In accordance with ANSI/AISC 360, a method was established for predicting uniaxial eccentric capacity. By conducting a parametric analysis of Mx/Mux,n-My/Muy,n curves, a simplified method for determining Mx/Mux,n-My/Muy,n curves was proposed, with calculation results in good agreement with FE results.
近年来，异形混凝土填充钢管（CFST）结构引起了学者们的极大兴趣。然而，对多单元 T 型 CFST（MT-CFST）柱的研究关注有限，导致计算方法缺乏统一性。本文提出了一种改进的 MT-CFST 柱，由三根矩形钢管、一块钢板和混凝土组成。这种设计可确保焊缝避开钢管的冷弯区，从而提高焊缝质量。在实际工程应用中，支柱经常会承受双轴偏心载荷。对 15 个 MT-CFST 试样进行了双轴偏心压缩试验。本研究探讨了偏心率、偏心角和腹板高度对 MT-CFST 柱性能的影响。实验结果表明，各试样的失效模式相似：在峰值载荷之前，都出现了轻微的弯曲变形。对于 T56.6-60-45° 和 T40-90-180° 试件，由于受压侧钢板的宽厚比较小，防止了局部屈曲。其他试样在靠近中跨部分的受压侧出现了轻微的局部屈曲。在峰值荷载之后，局部屈曲逐渐加剧，这主要是由于大量的弯曲变形造成的。试样的破坏归因于局部屈曲和整体弯曲变形。当偏心距大于 20 毫米时，试样的承载能力和弹塑性刚度随着偏心角的增大呈先增大后减小的趋势，峰值出现在 90°左右。受压侧位于凸缘的试样具有更高的承载能力和弹塑性刚度。此外，还建立了 FE 模型来模拟双向偏心行为。以极限条件下的截面应力分析为基础，开发了一种计算抗弯能力的简化方法。根据 ANSI/AISC 360 标准，建立了预测单轴偏心承载力的方法。通过对 Mx/Mux,n-My/Muy,n 曲线进行参数分析，提出了一种确定 Mx/Mux,n-My/Muy,n 曲线的简化方法，计算结果与 FE 结果十分吻合。
{"title":"Biaxial eccentric behavior of improved multi-cell T-shaped concrete-filled steel tubes","authors":"Chao Hu , Rui Cheng , Yuhang Wang , Meilan Gong , Jichun Liu","doi":"10.1016/j.jcsr.2024.109131","DOIUrl":"10.1016/j.jcsr.2024.109131","url":null,"abstract":"<div><div>The special-shaped concrete-filled steel tube (CFST) structure has attracted considerable scholarly interest in recent years. However, limited attention has been given to research on multi-cell T-shaped CFST (MT-CFST) column, resulting in a lack of uniformity in calculation methods. This paper presents an improved MT-CFST column composed of three rectangular steel tubes, a steel plate, and concrete. This design ensures that welds avoid cold bending zones in steel tubes, thereby enhancing quality of welds. In practical engineering applications, columns often experience biaxial eccentric loads. A biaxial eccentric compression test was conducted on fifteen MT-CFST specimens. This study investigated the influence of eccentricity, eccentric angle, and web height on performance of MT-CFST column. The experimental results revealed a similar failure mode among specimens: prior to peak load, minor bending deformation was observed. For specimens T56.6–60-45° and T40–90-180°, the smaller width-to-thickness ratio of steel plates on compressed side prevented local buckling. For other specimens, slight local buckling on compressed side near mid-span section was observed. After peak load, local buckling progressively intensified, primarily due to substantial bending deformation. The failure of specimens was attributed to local buckling and overall bending deformation. For eccentricity greater than 20 mm, the bearing capacity and elastic-plastic stiffness of specimens exhibited an increasing trend followed by a decreasing trend with the increase in eccentric angle at the same eccentricity, with the peaks occurring at around 90°. Specimens with the compressed side located at flange demonstrated higher bearing capacity and elastic-plastic stiffness. Additionally, FE models have been established to simulate the bidirectional eccentric behavior. A simplified method for calculating flexural capacity was developed, grounded in stress analysis of section at ultimate conditions. In accordance with ANSI/AISC 360, a method was established for predicting uniaxial eccentric capacity. By conducting a parametric analysis of <em>M</em><sub>x</sub>/<em>M</em><sub>ux,n</sub>-<em>M</em><sub>y</sub>/<em>M</em><sub>uy,n</sub> curves, a simplified method for determining <em>M</em><sub>x</sub>/<em>M</em><sub>ux,n</sub>-<em>M</em><sub>y</sub>/<em>M</em><sub>uy,n</sub> curves was proposed, with calculation results in good agreement with FE results.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109131"},"PeriodicalIF":4.0,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-04DOI: 10.1016/j.jcsr.2024.109141
Yu Shi , Jie Wang , Xuhong Zhou , Xuanyi Xue
This study included a series of experiments and a detailed numerical analysis to reveal the cross-sectional behaviors and residual compression ultimate capacities of cold-formed titanium-clad bimetallic steel (TCBS) angle section stub columns (ASSCs) following exposure to high temperatures. Four cold-formed TCBS ASSCs with different geometric dimensions were tested. The exposure temperature included 20 °C, 700 °C, and 900 °C. After experiment, a comprehensive numerical analysis was carried out, wherein 200 finite element models were included. Given the lack of specialized design approaches for cold-formed TCBS structures, the applicability of conventional design approaches for carbon steel structures to cold-formed TCBS ASSCs subjected to high temperatures was assessed, where the design approaches in EN 1993-1-1, AISI 100, and the Direct Strength Method were considered. It was found that the existing design approaches for post-fire cold-formed TCBS ASSCs lacked precision. Hence, modifications to the design approach in EN 1993-1-1 were proposed to improve the accuracy on the prediction of the residual compressive ultimate capacities of cold-formed TCBS ASSCs following exposure to high temperatures. This provided the foundation for evaluating the post-fire serviceability of cold-formed TCBS structures.
{"title":"Post-fire behavior of cold-formed titanium-clad bimetallic steel angle section stub columns","authors":"Yu Shi , Jie Wang , Xuhong Zhou , Xuanyi Xue","doi":"10.1016/j.jcsr.2024.109141","DOIUrl":"10.1016/j.jcsr.2024.109141","url":null,"abstract":"<div><div>This study included a series of experiments and a detailed numerical analysis to reveal the cross-sectional behaviors and residual compression ultimate capacities of cold-formed titanium-clad bimetallic steel (TCBS) angle section stub columns (ASSCs) following exposure to high temperatures. Four cold-formed TCBS ASSCs with different geometric dimensions were tested. The exposure temperature included 20 °C, 700 °C, and 900 °C. After experiment, a comprehensive numerical analysis was carried out, wherein 200 finite element models were included. Given the lack of specialized design approaches for cold-formed TCBS structures, the applicability of conventional design approaches for carbon steel structures to cold-formed TCBS ASSCs subjected to high temperatures was assessed, where the design approaches in EN 1993-1-1, AISI 100, and the Direct Strength Method were considered. It was found that the existing design approaches for post-fire cold-formed TCBS ASSCs lacked precision. Hence, modifications to the design approach in EN 1993-1-1 were proposed to improve the accuracy on the prediction of the residual compressive ultimate capacities of cold-formed TCBS ASSCs following exposure to high temperatures. This provided the foundation for evaluating the post-fire serviceability of cold-formed TCBS structures.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109141"},"PeriodicalIF":4.0,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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