摘要
针对预应力耗能(PTED)钢框架结构的连续倒塌问题,采用ABAQUS软件建立精细化有限元模型,对框架结构拆除承重构件后不平衡荷载重分配的行为展开研究。并将有限元结果与1/3缩尺PTED钢框架的准静态试验结果进行对比分析,验证了模型的准确性。在此基础上,进一步开展了PTED钢框架抗连续倒塌受力机制的研究,并分析了初始预应力、预应力钢绞线数量、钢构件材料强度和梁翼缘宽厚比四种因素对钢框架抗连续倒塌机制的影响。结果表明:PTED钢框架抗连续倒塌过程主要包括三个阶段:初始阶段、压拱机制有利阶段和压拱机制不利阶段;倒塌抗力由预应力钢绞线拉力和梁柱之间的竖向作用力共同提供;提高初始预应力、预应力钢绞线数量、钢材屈服强度和降低梁翼缘宽厚比,均会使峰值荷载增大;钢绞线数量的增多使框架在失效柱位移较小时可以提供较大的抗力;增强梁柱构件抵抗局部屈曲变形的能力会提升预应力钢框架抗连续倒塌能力。
Aiming at the progressive collapse of post⁃tensioned energy dissipating(PTED)steel frame structures,a refined finite element model was established by using ABAQUS software,and the behavior of unbalanced load redistribution was studied after the load⁃bearing members were removed.The accuracy of the model was verified by comparing the finite element results with test results of the quasi⁃static push⁃down of the 1/3⁃scale PTED steel frame.On this basis,further research on the mechanism of resisting progressive collapse of the PTED steel frame was carried out.The effects of four factors,namely,initial post⁃tensioned,number of post⁃tensioned steel strand,material strength of steel members,and the width⁃thickness ratio of beam flange on the resisting progressive collapse mechanism of steel frames were analyzed.The results show that there are three stages in the process of resisting progressive collapse of the PTED steel frame:the initial stage,the favorable stage and the unfavorable stage of arch compression mechanism.The collapse resistance is provided by the tensile force of post⁃tensioned steel strand and the vertical force between beam and column.Increasing initial post⁃tensioned force,number of post⁃tensioned steel strand,yield strength of steel and decreasing the width⁃thickness ratio of beam flange will increase the peak load.With the increase of the number of steel strands,the frame can provide greater resistance when the displacement of the failure column is small.Strengthening the ability of resisting local buckling deformation of beam⁃column members will improve the ability of resisting progressive collapse of PTED steel frames.
作者
王述红
陈浩
单思镝
魏崴
WANG Shuhong;CHEN Hao;SHAN Sidi;WEI Wei(School of Resources&Civil Engineering,Northeastern University,Shenyang 110819,China)
出处
《建筑结构》
北大核心
2024年第16期52-59,共8页
Building Structure
基金
国家自然科学基金资助项目(U1602232)
辽宁省科学技术计划重大项目(2019JH2/10100035)
中国-中东欧国家高校联合教育项目(2021111)
国家外专项目(DL2021128001L)。
关键词
自复位结构
预应力耗能钢框架
连续倒塌机制
抗力
self⁃centering structure
post⁃tensioned energy dissipating steel frame
progressive collapse mechanism
resistance force
