多层钢框架连续倒塌动力效应分析

Dynamic effect analysis of progressive collapse of multi-story steel frames

为研究多层钢框架连续倒塌由于初始破坏引起的动力效应,本文采用集中塑性铰杆模型,以需求能力比(DCR)为参数,利用瞬时加载法对一榀多层平面钢框架和一个多层空间钢框架进行了弹塑性动力反应分析。分析结果表明:随着DCR的增大,各柱列沿竖向动力放大效应基本不变;当DCR≤0.5时,随着DCR的增大,各柱列动力放大效应基本不变,且一般情况下含失效构件的柱列动力放大效应最显著;当DCR>0.5时,含失效构件的柱列动力放大效应随着DCR的增大而增大,其余柱列动力放大效应随着DCR的增大而减小或基本不变。

To study the dynamic effect resulted from the initial damage to the structure during progressive collapse, the lumped plastic hinge model and the instantaneously applied load method are adopted to perform the elasto-plastic dynamic response analysis of a multi-story plane steel frame and a multi-story spacial steel frame corresponding to various demand-capacity ratios （DCR） respectively. The analysis results indicate： with the increase of DCR, the dynamic amplifying effect remains approximately constant along the height of each column line; when DCR is less than or equal to 0.5, the dynamic amplifying effect of each column line remains approximately constant with the increase of DCR and that of the column line containing the failed member is most significant in general ; when DCR is larger than 0.5, the dynamic amplifying effect of the column line containing the failed member increases with the increase of DCR and that of other column lines decreases or remains unchanged.