基于Pushdown方法的圆钢管混凝土柱-钢梁框架抗连续倒塌机制分析

Progressive collapse-resistance mechanism analysis of composite frame with CFST columns and steel beams based on pushdown method

为研究结构在关键构件失效后的抗连续倒塌机制,基于ABAQUS纤维梁-柱单元建立了钢管混凝土柱-钢梁框架的有限元模型,钢材及核心混凝土材性分别调用课题组基于ABAQUS软件开发的材料本构子程序i Fiber LUT中的i Steel05和i Concrete01。采用Pushdown分析方法,对长边中柱失效、短边中柱失效、内部柱失效和角柱失效等4种典型工况下的连续倒塌进行了分析,研究典型柱失效后剩余结构的抗连续倒塌机制。研究结果表明:纤维梁-柱单元模型可以精准地分析空间框架连续倒塌性能。4种柱工况下结构的抗连续倒塌能力由大到小为:短边中柱失效、内部柱失效、长边中柱失效、和角柱失效。

In order to research the mechanism of progressive collapse when the key members destroyed,a finite element( FE) model of composite frame with concrete filled steel tubular( CFST) columns and steel beams was developed based on ABAOUS fiber beam-column element. The iS teel 0. 5 and iC oncrete 0. 1 in the material constitutive sub-program iF iber LUT developed by research group based on software ABAQUS were used for steel and core concrete material. Prograssive collapes analysis was carried out with pushdown analysis method for 4typical working condition,i. e. middle column failure on long side,middle column failure on short side,interior column failure and corner column failure,and the prograssive collapse-resistance mechanism of residual structure after typical column failure was researched. The results show that the fiber beam-column element model may analyze the performance of prograssive collapse of spatial frame,the sequence of prograsssive collapse-resistance capacity of the structure from large to small is middle column failure on short side. interior column failure,middle column failure on long side and corner column failure.