单层平面钢框架连续倒塌动力效应分析

为研究结构连续倒塌由于初始破坏引起的动力效应,该文采用瞬时加载法,对中柱失效的单层平面钢框架分别采用简化模型和杆单元模型进行动力反应分析。分析结果表明:当结构处于线弹性状态时,动力放大效应仅与构件失效时间和阻尼比有关,动力放大系数最大值为2,且随着构件失效时间和阻尼比的增大而减小;当结构屈服进入塑性状态后,动力放大效应还与需求能力比(DCR)有关,动力放大系数随着DCR的增大而增大,直至结构出现动力发散。

DYNAMIC EFFECT ANALYSIS DURING PROGRESSIVE COLLAPSE OF A SINGLE-STORY STEEL PLANE FRAME

To study dynamic effect resulted from the initial damage of the structure during progressive collapse, instantaneously applied load method was adopted to perform dynamic response analysis of a single-story steel plane frame with the failed middle column by a simplified model and frame element model respectively. The analytical results show that the dynamic amplifying effect depends only on damping ratio and the failure time of the member when the structure is elastic. The dynamic amplifying factor decreases with the increase of damping ratio or the failure time and the maximum value is 2. When the structure yields and behaves plastically, dynamic amplifying effect is also related to demand-capacity ratio (DCR) and it increases with the increase of DCR until dynamic divergence occurs.