Pub Date : 2025-03-29DOI: 10.1016/j.jcsr.2025.109535
Yichuan Wang , Yi-Fei Hu , Yawei Han , Huiyong Ban , Yongjiu Shi , Kwok-Fai Chung , Nancy Baddoo
This paper describes a series of structural tests on standardized coupons of stainless-clad (SC) bimetallic steel plates and their welded joints under various actions. Despite the clad layers of the stainless steel are bonded at a metallurgic level onto the substrate plate of carbon steel, it is important to establish that debonding of the clad layer from the substrate plate, i.e. an integrity failure within the SC plates, will not take place prematurely. These structural tests include i) debonding tests along the interfaces of the stainless steel and the carbon steel of the SC plates under shear and tension actions; ii) tension tests on the SC plates; iii) both tensile and bending tests on the welded joints of the SC plates. It is shown that among all these tests on the SC plates and their welded joints, the interfaces of the SC plates are very strong and fully intact under various global and local actions. The SC plates are considered to be highly effective, and enhancement provided by the clad layers of the stainless steel to the substrate plates of carbon steel is totally reliable up to its fracture. Moreover, the welded joints of the SC plates are always stronger than their base plates under the effects of welding. Consequently, it is demonstrated that these SC plates are able to meet various stringent structural requirements in construction, and they are able to sustain large applied loads even up to large deformations.
{"title":"Monotonic behaviour of stainless-clad bimetallic steel and their welded joints","authors":"Yichuan Wang , Yi-Fei Hu , Yawei Han , Huiyong Ban , Yongjiu Shi , Kwok-Fai Chung , Nancy Baddoo","doi":"10.1016/j.jcsr.2025.109535","DOIUrl":"10.1016/j.jcsr.2025.109535","url":null,"abstract":"<div><div>This paper describes a series of structural tests on standardized coupons of stainless-clad (SC) bimetallic steel plates and their welded joints under various actions. Despite the clad layers of the stainless steel are bonded at a metallurgic level onto the substrate plate of carbon steel, it is important to establish that debonding of the clad layer from the substrate plate, i.e. an integrity failure within the SC plates, will <em>not</em> take place prematurely. These structural tests include i) debonding tests along the interfaces of the stainless steel and the carbon steel of the SC plates under shear and tension actions; ii) tension tests on the SC plates; iii) both tensile and bending tests on the welded joints of the SC plates. It is shown that among all these tests on the SC plates and their welded joints, the interfaces of the SC plates are very strong and fully intact under various global and local actions. The SC plates are considered to be highly effective, and enhancement provided by the clad layers of the stainless steel to the substrate plates of carbon steel is totally reliable up to its fracture. Moreover, the welded joints of the SC plates are always stronger than their base plates under the effects of welding. Consequently, it is demonstrated that these SC plates are able to meet various stringent structural requirements in construction, and they are able to sustain large applied loads even up to large deformations.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"229 ","pages":"Article 109535"},"PeriodicalIF":4.0,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724924","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 : 2025-03-29DOI: 10.1016/j.jcsr.2025.109531
Zichang Yang , Yufei Zhu , Song Su , Yu Chen , Cheng Huang , Guo-Qiang Li
A comprehensive experimental and numerical study on the cross-sectional load-carrying behaviour of cold-formed stainless-steel square and rectangular hollow section (SHS/RHS) beams under the effect of moment gradients is presented in this paper. Three four-point bending tests and six three-point bending tests were first conducted on cold-drawn austenitic stainless-steel SHS beams with various moment gradients. Digital image correlation (DIC) system was employed to monitor the strain development during the tests. Validated finite element (FE) models were developed to simulate the structural performance of cold-formed SHS and RHS beams and were subsequently used in a numerical parametric study to generate a comprehensive dataset covering a wide range of cross-sectional geometries, materials, and moment distributions. The results showed that the bending moment capacity of stainless-steel SHS and RHS beams is enhanced by the presence of moment gradients, with the magnitude of enhancement being highly related to the cross-section slenderness. This study refines and extends a recent design proposal that introduces a parameter to capture the effect of moment gradients on the local buckling capacity of beams, aligning with EN 1993-1-1:2023, to stainless-steel SHS and RHS beams. The effectiveness of the proposal under the framework of prEN 1993-1-4:2023 was evaluated using experimental and numerical results. The approach was found to consistently provide more accurate resistance predictions than the current EC3 design rules for stainless-steel SHS and RHS beams under combined shear and moment. The reliability of the proposed method was further validated through statistical analyses in accordance with EN 1990:2023.
{"title":"Moment gradient effects on load-carrying capacity of stainless-steel SHS and RHS beams","authors":"Zichang Yang , Yufei Zhu , Song Su , Yu Chen , Cheng Huang , Guo-Qiang Li","doi":"10.1016/j.jcsr.2025.109531","DOIUrl":"10.1016/j.jcsr.2025.109531","url":null,"abstract":"<div><div>A comprehensive experimental and numerical study on the cross-sectional load-carrying behaviour of cold-formed stainless-steel square and rectangular hollow section (SHS/RHS) beams under the effect of moment gradients is presented in this paper. Three four-point bending tests and six three-point bending tests were first conducted on cold-drawn austenitic stainless-steel SHS beams with various moment gradients. Digital image correlation (DIC) system was employed to monitor the strain development during the tests. Validated finite element (FE) models were developed to simulate the structural performance of cold-formed SHS and RHS beams and were subsequently used in a numerical parametric study to generate a comprehensive dataset covering a wide range of cross-sectional geometries, materials, and moment distributions. The results showed that the bending moment capacity of stainless-steel SHS and RHS beams is enhanced by the presence of moment gradients, with the magnitude of enhancement being highly related to the cross-section slenderness. This study refines and extends a recent design proposal that introduces a parameter to capture the effect of moment gradients on the local buckling capacity of beams, aligning with EN 1993-1-1:2023, to stainless-steel SHS and RHS beams. The effectiveness of the proposal under the framework of prEN 1993-1-4:2023 was evaluated using experimental and numerical results. The approach was found to consistently provide more accurate resistance predictions than the current EC3 design rules for stainless-steel SHS and RHS beams under combined shear and moment. The reliability of the proposed method was further validated through statistical analyses in accordance with EN 1990:2023.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"229 ","pages":"Article 109531"},"PeriodicalIF":4.0,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724923","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 : 2025-03-27DOI: 10.1016/j.jcsr.2025.109533
Hesam Azizi, Jamal Ahmadi
This investigation introduces a novel all-steel Y-shaped HBRB (YHBRB) incorporating three cores with varying yield strengths to enhance the seismic resilience of these brace types. The mechanical properties of the YHBRB were derived theoretically. Then, a numerical investigation was undertaken to elucidate the factors influencing its hysteretic behavior, encompassing hysteresis curves, backbone curves, stiffness degradation, cumulative energy dissipation, equivalent damping ratio, self-centering capacity, and other pertinent mechanical indices, through the application of finite element analysis. To detect the optimal core material combination for YHBRB, a parametric study was conducted on various high-performance materials, considering their impact on the cyclic behavior of the YHBRB. In the second phase of this investigation, a comparative analysis was conducted to evaluate the efficacy of the proposed YHBRB design methodology. Four prototypical braced frame configurations, each incorporating YHBRBs, were subjected to numerical simulations. These models were compared against conventional buckling-restrained braced (BRB) frames and hybrid BRB (HBRB) frames to facilitate a comprehensive assessment. Nonlinear dynamic analyses were executed under four distinct seismic hazard levels to quantify the seismic performance of these structures. The results demonstrate that YHBRB frames exhibit superior performance. YHBRB frames show a substantial reduction in residual drift compared to HBRB frames, especially BRB frames, in damage mitigation.
{"title":"Mitigation of residual deformations in steel braced frames through an innovative Y-shaped hybrid buckling restrained braces","authors":"Hesam Azizi, Jamal Ahmadi","doi":"10.1016/j.jcsr.2025.109533","DOIUrl":"10.1016/j.jcsr.2025.109533","url":null,"abstract":"<div><div>This investigation introduces a novel all-steel Y-shaped HBRB (YHBRB) incorporating three cores with varying yield strengths to enhance the seismic resilience of these brace types. The mechanical properties of the YHBRB were derived theoretically. Then, a numerical investigation was undertaken to elucidate the factors influencing its hysteretic behavior, encompassing hysteresis curves, backbone curves, stiffness degradation, cumulative energy dissipation, equivalent damping ratio, self-centering capacity, and other pertinent mechanical indices, through the application of finite element analysis. To detect the optimal core material combination for YHBRB, a parametric study was conducted on various high-performance materials, considering their impact on the cyclic behavior of the YHBRB. In the second phase of this investigation, a comparative analysis was conducted to evaluate the efficacy of the proposed YHBRB design methodology. Four prototypical braced frame configurations, each incorporating YHBRBs, were subjected to numerical simulations. These models were compared against conventional buckling-restrained braced (BRB) frames and hybrid BRB (HBRB) frames to facilitate a comprehensive assessment. Nonlinear dynamic analyses were executed under four distinct seismic hazard levels to quantify the seismic performance of these structures. The results demonstrate that YHBRB frames exhibit superior performance. YHBRB frames show a substantial reduction in residual drift compared to HBRB frames, especially BRB frames, in damage mitigation.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"229 ","pages":"Article 109533"},"PeriodicalIF":4.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704805","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 : 2025-03-26DOI: 10.1016/j.jcsr.2025.109534
Yuheng Wang , Rui Wang , Yiwu Tian , Hui Zhao , Wensu Chen , Rong Zhang
This study presents the test and numerical investigations on the behaviours of hollow circular steel (HCS) tubes under coupled actions of transverse impact and low temperatures. Thirteen HCS tubes were prepared and tested to evaluate the influences of the low temperature, impact energy and steel tube thickness on the impact-resistance performance. The failure pattern, mid-span deformation and impact force were obtained and analyzed. Test results showed that HCS tubes experienced significant local deformation and global deflection under lateral impact. As the temperature dropped from 20 °C to −70 °C, the plateau impact force increased by 13.4 %–20.8 %, while the maximum deflection decreased by 15.1 %–27.1 %. In addition, finite element (FE) models were developed and validated against the test data. With the validated numerical model, dynamic response and working mechanism of HCS tubes were further investigated through analyses of the full-range motion and stress distribution. Local indentation primarily developed during the initial impact phase, while global deflection reached its peak at the end of the plateau phase. During the declining phase, the stress in the steel tube decreased as the elastic deformation recovered. Based on the experimental and numerical results, an empirical formula was proposed for predicting the local deformation of HCS tubes subjected to the combined effects of impact and low temperatures. This formula incorporated the influences of temperature, tube thickness, tube length, tube diameter, impact velocity, and impact mass. Generally, the empirical formula provides accurate prediction.
{"title":"Impact performance of hollow steel tubes under low temperatures","authors":"Yuheng Wang , Rui Wang , Yiwu Tian , Hui Zhao , Wensu Chen , Rong Zhang","doi":"10.1016/j.jcsr.2025.109534","DOIUrl":"10.1016/j.jcsr.2025.109534","url":null,"abstract":"<div><div>This study presents the test and numerical investigations on the behaviours of hollow circular steel (HCS) tubes under coupled actions of transverse impact and low temperatures. Thirteen HCS tubes were prepared and tested to evaluate the influences of the low temperature, impact energy and steel tube thickness on the impact-resistance performance. The failure pattern, mid-span deformation and impact force were obtained and analyzed. Test results showed that HCS tubes experienced significant local deformation and global deflection under lateral impact. As the temperature dropped from 20 °C to −70 °C, the plateau impact force increased by 13.4 %–20.8 %, while the maximum deflection decreased by 15.1 %–27.1 %. In addition, finite element (FE) models were developed and validated against the test data. With the validated numerical model, dynamic response and working mechanism of HCS tubes were further investigated through analyses of the full-range motion and stress distribution. Local indentation primarily developed during the initial impact phase, while global deflection reached its peak at the end of the plateau phase. During the declining phase, the stress in the steel tube decreased as the elastic deformation recovered. Based on the experimental and numerical results, an empirical formula was proposed for predicting the local deformation of HCS tubes subjected to the combined effects of impact and low temperatures. This formula incorporated the influences of temperature, tube thickness, tube length, tube diameter, impact velocity, and impact mass. Generally, the empirical formula provides accurate prediction.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"229 ","pages":"Article 109534"},"PeriodicalIF":4.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704804","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 : 2025-03-26DOI: 10.1016/j.jcsr.2025.109529
Ming Chen , Yu Geng , Bushuan Li , Weibo Lu , Fangqi Hu , Xiangyu Zhang , Yuhang Guo
This paper proposes a cold-formed thin-walled steel (CFS) frame structure with fully bolted connections, which can solve the challenges associated with beam-column joints that cannot be connected. It takes into account the issues of discontinuous vertical load transfer and the insufficient horizontal load resistance capacity of traditional “box” structure. To grasp the lateral load-resisting performance of the cruciform CFS built-up columns in the above structure, the cross-sectional dimensions and effective lengths will be considered as parameters. Experimental tests were carried out on six built-up columns to investigate the failure modes and lateral load-resisting performance under cyclic reversed loading tests at first. Secondly, a nonlinear finite element model of such built-up columns was established based on ABAQUS software, and validated against experimental results. The influence of axial compression ratio, web height to plate thickness ratio, and overall slenderness ratio were analyzed so as to further understand the influence of main parameters on the lateral load-resisting performance. Finally, the stiffness degradation characteristics in lateral load-resisting were proposed. The research results indicated that the built-up column experienced complete loading process, resulting in plastic cracks that occurred global flexural failure due to severe buckling deformation at the bottom flange-web joint of the column limb. Meanwhile, it shows good ductility, deformation, and energy dissipation ability. Regarding the specimens with the same effective length, when the height of the web increased from 105 mm to 135 mm and then to 195 mm, the ultimate capacity of the specimens increased by at least 49.48 % and 110.15 %, respectively. However, when the effective length was reduced from 1950 mm to 1250 mm, the ultimate capacity of the specimen increased by at least 39.35 %, despite the same cross-sectional dimension. Therefore, compared to the effective length, the cross-sectional dimension has a significant influence on the lateral bearing capacity. Additionally, compared with axial compression ratio, the web height to plate thickness ratio and overall slenderness ratio had significant influence on the lateral bearing capacity and initial stiffness.
{"title":"Research on lateral load-resisting performance of cruciform cold-formed steel built-up columns","authors":"Ming Chen , Yu Geng , Bushuan Li , Weibo Lu , Fangqi Hu , Xiangyu Zhang , Yuhang Guo","doi":"10.1016/j.jcsr.2025.109529","DOIUrl":"10.1016/j.jcsr.2025.109529","url":null,"abstract":"<div><div>This paper proposes a cold-formed thin-walled steel (CFS) frame structure with fully bolted connections, which can solve the challenges associated with beam-column joints that cannot be connected. It takes into account the issues of discontinuous vertical load transfer and the insufficient horizontal load resistance capacity of traditional “box” structure. To grasp the lateral load-resisting performance of the cruciform CFS built-up columns in the above structure, the cross-sectional dimensions and effective lengths will be considered as parameters. Experimental tests were carried out on six built-up columns to investigate the failure modes and lateral load-resisting performance under cyclic reversed loading tests at first. Secondly, a nonlinear finite element model of such built-up columns was established based on ABAQUS software, and validated against experimental results. The influence of axial compression ratio, web height to plate thickness ratio, and overall slenderness ratio were analyzed so as to further understand the influence of main parameters on the lateral load-resisting performance. Finally, the stiffness degradation characteristics in lateral load-resisting were proposed. The research results indicated that the built-up column experienced complete loading process, resulting in plastic cracks that occurred global flexural failure due to severe buckling deformation at the bottom flange-web joint of the column limb. Meanwhile, it shows good ductility, deformation, and energy dissipation ability. Regarding the specimens with the same effective length, when the height of the web increased from 105 mm to 135 mm and then to 195 mm, the ultimate capacity of the specimens increased by at least 49.48 % and 110.15 %, respectively. However, when the effective length was reduced from 1950 mm to 1250 mm, the ultimate capacity of the specimen increased by at least 39.35 %, despite the same cross-sectional dimension. Therefore, compared to the effective length, the cross-sectional dimension has a significant influence on the lateral bearing capacity. Additionally, compared with axial compression ratio, the web height to plate thickness ratio and overall slenderness ratio had significant influence on the lateral bearing capacity and initial stiffness.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"229 ","pages":"Article 109529"},"PeriodicalIF":4.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697980","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 : 2025-03-24DOI: 10.1016/j.jcsr.2025.109528
Wenhao Liu , Bin Zeng , Yongwei Wang , Kaiping Jiang , Zhen Zhou
Given that localized corroded circular steel tube (LCCST) members are more prone to ultra-low cycle fatigue (ULCF) failure under seismic action, this study first conducts electrochemical accelerated corrosion tests to simulate the localized corrosion of circular steel tube (CST) members. Subsequently, ULCF tests are performed on 13 CST members to analyze the effects of different parameters on the failure modes and ULCF performance. The test results show that the hysteresis curves of the LCCST members are clearly asymmetric, and that corrosion could seriously affect the ULCF performance of the CST members. As the corrosion ratio increases, the load-bearing capacity and stiffness significantly decrease. In addition, the specimens are mainly characterized by buckling instability failure in compression and fracture owing to damage accumulation in tension. For members with a large slenderness ratio, the post-buckling segment decreases linearly, whereas that of members with a small slenderness ratio decreases nonlinearly. With an increase in the corrosion and circumferential corrosion ratios, the post-buckling segment gradually transforms from nonlinear to linear. Finally, a finite element (FE) model of the LCCSTs is established, and the verified FE model can better simulate the failure modes and ULCF performance of the specimens. The parametric analysis shows that the corrosion location has a limited effect on the ultimate load-bearing capacity but affects the location of the fracture. The length of longitudinal corrosion has a limited effect on the ultimate load-bearing capacity.
{"title":"Experimental and numerical investigation on ultra-low cycle fatigue performance of LCCST members","authors":"Wenhao Liu , Bin Zeng , Yongwei Wang , Kaiping Jiang , Zhen Zhou","doi":"10.1016/j.jcsr.2025.109528","DOIUrl":"10.1016/j.jcsr.2025.109528","url":null,"abstract":"<div><div>Given that localized corroded circular steel tube (LCCST) members are more prone to ultra-low cycle fatigue (ULCF) failure under seismic action, this study first conducts electrochemical accelerated corrosion tests to simulate the localized corrosion of circular steel tube (CST) members. Subsequently, ULCF tests are performed on 13 CST members to analyze the effects of different parameters on the failure modes and ULCF performance. The test results show that the hysteresis curves of the LCCST members are clearly asymmetric, and that corrosion could seriously affect the ULCF performance of the CST members. As the corrosion ratio increases, the load-bearing capacity and stiffness significantly decrease. In addition, the specimens are mainly characterized by buckling instability failure in compression and fracture owing to damage accumulation in tension. For members with a large slenderness ratio, the post-buckling segment decreases linearly, whereas that of members with a small slenderness ratio decreases nonlinearly. With an increase in the corrosion and circumferential corrosion ratios, the post-buckling segment gradually transforms from nonlinear to linear. Finally, a finite element (FE) model of the LCCSTs is established, and the verified FE model can better simulate the failure modes and ULCF performance of the specimens. The parametric analysis shows that the corrosion location has a limited effect on the ultimate load-bearing capacity but affects the location of the fracture. The length of longitudinal corrosion has a limited effect on the ultimate load-bearing capacity.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"229 ","pages":"Article 109528"},"PeriodicalIF":4.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685260","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 : 2025-03-21DOI: 10.1016/j.jcsr.2025.109530
Weiyong Wang , Zhuofan Li , Siqi Li
This study explored the influence of stress levels on the residual mechanical properties of Q960 high strength steel after exposure to temperatures ranging from 300 °C to 800 °C. While many studies on post-fire mechanical properties of high strength steel neglect the presence of stress during heating and cooling, this research addresses this gap by conducting tensile tests under three pre-tension ratios. The results show that, in the temperature range of 300 °C–500 °C, constant tensile stress enhances the residual yield strength and ultimate strength of Q960 steel, with ultimate strength increasing by up to 7 %. However, at temperatures above 600 °C, tensile stress adversely affects these properties. Furthermore, the residual elastic modulus of Q960 steel remains largely unaffected by tensile stress. Comparisons with Q690 high strength steel reveal that pre-tension has a weaker influence on the residual yield strength of Q960 steel but a stronger detrimental effect at higher temperatures. Additionally, compared to S960 high strength steel (nominal yield strength: 960 MPa), Q960 steel demonstrates superior residual ultimate and yield strengths after high-temperature exposure, while S960 exhibits greater sensitivity to temperature changes in terms of elastic modulus. Compared to other 960 MPa high strength steels, Q960 CTUS (Cold-Formed Thick-Walled Ultra-High-Strength Steel) shows an increase in residual yield strength when exposed to temperatures between 300 °C–600 °C. These findings highlight the critical role of stress levels and temperature in determining the post-fire mechanical performance of high strength steel.
{"title":"Post-fire residual mechanical properties of high strength Q960 steel considering tensile stress in fire","authors":"Weiyong Wang , Zhuofan Li , Siqi Li","doi":"10.1016/j.jcsr.2025.109530","DOIUrl":"10.1016/j.jcsr.2025.109530","url":null,"abstract":"<div><div>This study explored the influence of stress levels on the residual mechanical properties of Q960 high strength steel after exposure to temperatures ranging from 300 °C to 800 °C. While many studies on post-fire mechanical properties of high strength steel neglect the presence of stress during heating and cooling, this research addresses this gap by conducting tensile tests under three pre-tension ratios. The results show that, in the temperature range of 300 °C–500 °C, constant tensile stress enhances the residual yield strength and ultimate strength of Q960 steel, with ultimate strength increasing by up to 7 %. However, at temperatures above 600 °C, tensile stress adversely affects these properties. Furthermore, the residual elastic modulus of Q960 steel remains largely unaffected by tensile stress. Comparisons with Q690 high strength steel reveal that pre-tension has a weaker influence on the residual yield strength of Q960 steel but a stronger detrimental effect at higher temperatures. Additionally, compared to S960 high strength steel (nominal yield strength: 960 MPa), Q960 steel demonstrates superior residual ultimate and yield strengths after high-temperature exposure, while S960 exhibits greater sensitivity to temperature changes in terms of elastic modulus. Compared to other 960 MPa high strength steels, Q960 CTUS (Cold-Formed Thick-Walled Ultra-High-Strength Steel) shows an increase in residual yield strength when exposed to temperatures between 300 °C–600 °C. These findings highlight the critical role of stress levels and temperature in determining the post-fire mechanical performance of high strength steel.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"229 ","pages":"Article 109530"},"PeriodicalIF":4.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685259","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 : 2025-03-20DOI: 10.1016/j.jcsr.2025.109527
P. Anand Aditya , Karuparambath Muhammed Navvar , Jayapal Kottalage Bahubali , Muhamed Safeer Pandikkadavath , Sujith Mangalathu
Corrosion is a critical factor affecting the durability, safety, and structural integrity of steel frame buildings, particularly in environments with high humidity, saline exposure, or industrial pollutants. This study explores the near-field seismic vulnerability of steel moment-resisting frames accounting for the effects of corrosion. Numerical models with and without accounting the corrosion effects are generated for steel frame buildings with various storey heights and bay span lengths, and the demand model is estimated through the generation of incremental dynamic analysis resulted curves. The demand is convolved with the capacity models to generate the fragility curves, and the impact assessment is carried out through a systematic comparison of the fragility curves. The fragility curves based on the inter-storey drift and the residual drift ratios revealed that the seismic vulnerability of the steel moment resisting frames increases irrespective of the bay span length and the frame height. The current study underscores the importance of considering corrosion and near-field seismicity for reliable risk assessment of steel structures situated in these regions.
{"title":"Near-fault seismic vulnerability assessment of corrosion inflicted steel moment resisting frames","authors":"P. Anand Aditya , Karuparambath Muhammed Navvar , Jayapal Kottalage Bahubali , Muhamed Safeer Pandikkadavath , Sujith Mangalathu","doi":"10.1016/j.jcsr.2025.109527","DOIUrl":"10.1016/j.jcsr.2025.109527","url":null,"abstract":"<div><div>Corrosion is a critical factor affecting the durability, safety, and structural integrity of steel frame buildings, particularly in environments with high humidity, saline exposure, or industrial pollutants. This study explores the near-field seismic vulnerability of steel moment-resisting frames accounting for the effects of corrosion. Numerical models with and without accounting the corrosion effects are generated for steel frame buildings with various storey heights and bay span lengths, and the demand model is estimated through the generation of incremental dynamic analysis resulted curves. The demand is convolved with the capacity models to generate the fragility curves, and the impact assessment is carried out through a systematic comparison of the fragility curves. The fragility curves based on the inter-storey drift and the residual drift ratios revealed that the seismic vulnerability of the steel moment resisting frames increases irrespective of the bay span length and the frame height. The current study underscores the importance of considering corrosion and near-field seismicity for reliable risk assessment of steel structures situated in these regions.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"229 ","pages":"Article 109527"},"PeriodicalIF":4.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685258","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 : 2025-03-20DOI: 10.1016/j.jcsr.2025.109524
Qi An , Yuhao Dong , Zhenzhou Bao , Xiujun Wang , Xiuli Liu , Zhiyu Pan
As modern society rapidly evolves, traditional large-span floor structures increasingly fail to meet the demands of modern large-span spaces. This study introduces an innovative spatial cable supported composite floor system. Field tests and finite element analyses, accounting for the construction process, were conducted to evaluate the overall deformation capacity, bearing capacity, and key parameter influences of the structure under vertical static loads. Test results reveal that when the load reaches 1.4 times the basic combined load, the mid-span deflection is 5.03 mm—just one-third of the allowable value specified in the code—demonstrating the excellent bearing performance of the spatial cable-supported composite floor. Finite element simulation results indicate that the construction process impacts the floor's bearing performance. The inclusion of the cable-strut system significantly enhances the floor's ultimate bearing capacity and allows for coordinated deformation with the upper structure. Compared to a conventional primary and secondary beam floor, the composite floor's bearing capacity increases by 22 %. The inner and outer cable-strut systems serve distinct roles and exhibit spatial force transmission characteristics.
{"title":"Study on static mechanical behavior of spatial cable supported composite floor system","authors":"Qi An , Yuhao Dong , Zhenzhou Bao , Xiujun Wang , Xiuli Liu , Zhiyu Pan","doi":"10.1016/j.jcsr.2025.109524","DOIUrl":"10.1016/j.jcsr.2025.109524","url":null,"abstract":"<div><div>As modern society rapidly evolves, traditional large-span floor structures increasingly fail to meet the demands of modern large-span spaces. This study introduces an innovative spatial cable supported composite floor system. Field tests and finite element analyses, accounting for the construction process, were conducted to evaluate the overall deformation capacity, bearing capacity, and key parameter influences of the structure under vertical static loads. Test results reveal that when the load reaches 1.4 times the basic combined load, the mid-span deflection is 5.03 mm—just one-third of the allowable value specified in the code—demonstrating the excellent bearing performance of the spatial cable-supported composite floor. Finite element simulation results indicate that the construction process impacts the floor's bearing performance. The inclusion of the cable-strut system significantly enhances the floor's ultimate bearing capacity and allows for coordinated deformation with the upper structure. Compared to a conventional primary and secondary beam floor, the composite floor's bearing capacity increases by 22 %. The inner and outer cable-strut systems serve distinct roles and exhibit spatial force transmission characteristics.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"229 ","pages":"Article 109524"},"PeriodicalIF":4.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685257","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 : 2025-03-19DOI: 10.1016/j.jcsr.2025.109513
Zhijian Yang, Lisuo Sun, Mo Liu
High-strength spiral-confined high-strength concrete-filled high-strength square steel tube (HSS-CHCFHSST) columns are a novel type of composite column. Embedding high-strength spirals (HSS) can improve the ductility of high-strength concrete-filled high-strength square steel tube (HCFHSST) columns. This study aims to evaluate the fundamental performance of HSS-CHCFHSST long columns under axial compression. A series of tests were conducted on axially compressed HSS-CHCFHSST long columns. The strength of the concrete (fc’) was 90 MPa. The maximum yield strengths of the steel tubes and spirals were 818 MPa and 1561 MPa, respectively. The finite element model of HSS-CHCFHSST long columns was also established. The results indicate that after reaching peak load, HSS-CHCFHSST long columns with a slenderness ratio of less than 27.71 exhibit deformation and ultimately fail during testing. As the slenderness ratio increases from 13.86 to 55.43, there is a corresponding decrease in axial compressive capacity by 28.74 %. When the slenderness ratio exceeds 40, the beneficial effect of HSS on enhancing ductility in HCFHSST long columns becomes minimal. Regression analysis was used to propose equations predicting the stability capacity of HSS-CHCFHSST axial compression columns, and their applicability was validated by comparison with experimental data and finite element analysis.
{"title":"Axial compressive performance of high-strength spiral-confined high-strength concrete-filled high-strength square-steel-tube long columns","authors":"Zhijian Yang, Lisuo Sun, Mo Liu","doi":"10.1016/j.jcsr.2025.109513","DOIUrl":"10.1016/j.jcsr.2025.109513","url":null,"abstract":"<div><div>High-strength spiral-confined high-strength concrete-filled high-strength square steel tube (HSS-CHCFHSST) columns are a novel type of composite column. Embedding high-strength spirals (HSS) can improve the ductility of high-strength concrete-filled high-strength square steel tube (HCFHSST) columns. This study aims to evaluate the fundamental performance of HSS-CHCFHSST long columns under axial compression. A series of tests were conducted on axially compressed HSS-CHCFHSST long columns. The strength of the concrete (<em>f</em><sub>c</sub><sup>’</sup>) was 90 MPa. The maximum yield strengths of the steel tubes and spirals were 818 MPa and 1561 MPa, respectively. The finite element model of HSS-CHCFHSST long columns was also established. The results indicate that after reaching peak load, HSS-CHCFHSST long columns with a slenderness ratio of less than 27.71 exhibit deformation and ultimately fail during testing. As the slenderness ratio increases from 13.86 to 55.43, there is a corresponding decrease in axial compressive capacity by 28.74 %. When the slenderness ratio exceeds 40, the beneficial effect of HSS on enhancing ductility in HCFHSST long columns becomes minimal. Regression analysis was used to propose equations predicting the stability capacity of HSS-CHCFHSST axial compression columns, and their applicability was validated by comparison with experimental data and finite element analysis.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"229 ","pages":"Article 109513"},"PeriodicalIF":4.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143654772","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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