铁道科学与工程学报2025，Vol.22Issue(3)：1229-1242,14.DOI:10.19713/j.cnki.43-1423/u.T20250106
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
摘要
Abstract
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 flange,the gradually straightening reinforcing plates collaborate with the remaining section to bear the load,significantly enhancing the secondary load-bearing capacity of the connection.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Key words
progressive collapse/reduced beam section joint/V-shaped reinforcing plate/static test/load resisting mechanism分类
建筑与水利引用本文复制引用
乔惠云,林誉,韦建刚,罗霞,魏建鹏..翼缘削弱改进型节点的抗连续倒塌分析[J].铁道科学与工程学报,2025,22(3):1229-1242,14.基金项目
国家自然科学基金资助项目(52278158,52408142) （52278158,52408142）
福建省自然科学基金资助项目(2024J01151) （2024J01151）
福州科技计划项目(2024-G-012) （2024-G-012）
