翼缘削弱改进型节点的抗连续倒塌分析  

Progressive collapse resistance of improved joints with reduced beam sections

作　　者：乔惠云 林誉 韦建刚 罗霞 魏建鹏 QIAO Huiyun;LIN Yu;WEI Jiangang;LUO Xia;WEI Jianpeng(School of Civil Engineering,Fujian University of Technology,Fuzhou 350118,China;School of Civil Engineering,Anhui Jianzhu University,Hefei 230601,China)

机构地区：[1]福建理工大学土木工程学院,福建福州350118 [2]安徽建筑大学土木工程学院,安徽合肥230601

出　　处：《铁道科学与工程学报》2025年第3期1229-1242,共14页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(52278158,52408142);福建省自然科学基金资助项目(2024J01151);福州科技计划项目(2024-G-012)。

摘　　要：为提高梁翼缘削弱截面(RBS)节点在极端荷载下的冗余度,增强钢框架结构的抗连续倒塌能力,提出一种在RBS节点布置加强板的改进方案。先对加强板改进RBS试件进行拟静力试验,系统研究试件的破坏模式、竖向变形及抗力发展规律。试验结果表明,加强板在小变形阶段作用有限,但随着变形增大,加强板逐渐拉直作为替代路径,协助钢梁承受荷载,使试件的变形能力和承载能力分别提高了21.7%和21.8%。进一步引入悬链线贡献系数和弯曲贡献系数对总抗力的影响,加强板与钢梁的协同作用提高悬链线效应,且悬链线贡献系数为基础试件的1.84倍。随后基于验证后的数值模型,研究加强板和翼缘削弱等对节点性能的影响。研究结果表明:翼缘削弱深度和加强板弯曲高度影响试件的破坏模式,根据钢梁的破坏位置分为Mode Ⅰ和Mode Ⅱ2种类型:Mode Ⅰ的裂缝始于翼缘削弱处,Mode Ⅱ的裂缝始于梁柱焊缝附近。削弱深度取规范建议上限值时,破坏模式为Mode Ⅰ,峰值荷载随加强板弯曲高度降低而增加,采用规范建议的下限值时,承载能力随加强板弯曲高度先升高后降低。同时,试件峰值荷载随着削弱深度的增加,呈现先升后降的变化规律。初始开裂发生在翼缘削弱处时,逐渐拉直的加强板能够与剩余截面协同受力,显著提升节点的二次承载能力。To improve the redundancy of reduced beam section(RBS)connections under extreme loads and enhance the resistance of steel frame structures to progressive collapse,an improved design incorporating reinforcing plates into RBS connections was proposed.Quasi-static tests were first conducted on RBS specimens with reinforcing plates to investigate their failure modes,vertical deformation,and resistance development.The test results show that the reinforcing plates have limited effects during the early deformation stage,but as deformation increases,the plates gradually straighten and serve as an alternative load path to assist the steel beams in bearing loads,resulting in an increase of 21.7% in deformation capacity and 21.8% in load-bearing capacity compared to the base specimen.To further introduce the contribution coefficients of flexural and catenary actions to the total resistance,the results revealed that the combined action of the reinforcing plates and the steel beam significantly enhanced the catenary action,with the catenary contribution coefficient being 1.84 times that of the base specimen.Subsequently,a validated numerical model is used to study the effects of flange reduction and reinforcing plates on connection performance.The results show that the flange reduction depth and the bending height of the reinforcing plates influence the failure modes,which can be categorized into two types based on the failure location of the steel beams:Mode Ⅰ,where cracking initiates at the reduced flange area,and Mode Ⅱ,where cracking begins near the beam-column weld.When the reduction depth reaches the upper limit recommended by the code,the failure mode is Mode Ⅰ,and the peak load increases as the plate height decreases.Conversely,when the reduction depth adheres to the lower limit,the load-carrying capacity first increases and then decreases with the plate height.Additionally,the peak load exhibits a trend of first increasing and then decreasing with the reduction depth.When initial cracking occurs at the reduced

关 键 词：连续倒塌 翼缘削弱节点 V型加强板 静力试验 抗力机制 

分 类 号：TU973[建筑科学—结构工程]