基于楼板薄膜效应的钢框架抗连续倒塌研究

PROGRESSIVE COLLAPSE ANALYSIS OF STEEL FRAME STRUCTURE BASED ON MEMBRANE ACTION OF COMPOSITE FLOOR SLABS

组合楼板作为钢框架结构的主要构件,在支撑柱失效情况下能产生很大的挠度,进而产生薄膜效应影响结构的抗连续倒塌性能。通过研究楼板挠曲悬链线阶段组合楼板薄膜效应对多层钢框架抗连续倒塌性能的影响,分析组合楼板在连续倒塌过程中的受力,提出考虑楼板薄膜效应的结构承载力计算方法。通过有限元分析软件进行框架连续倒塌分析,验证计算方法的准确性,探讨楼板对塑性铰发展、结构极限承载力、失效点位移的影响。研究表明:组合楼板能显著提高结构的抗连续倒塌性能。

Composite floor slab,as one of major steel frame structure elements,can have a significant deformation and could greatly influence the anti-progressive collapse performance through membrane action in the case of the column failure. It was mainly investigated the effect of the membrane action in the composite floor slabs on the anti-progressive collapse performance of multilayer steel frame in catenary stage,and a calculating method was proposed for computing the load-resisting capacity of composite floors subjected to the failure of interior column. In order to validate the calculation method and investigate the slab＇s effects on plastic hinges,ultimate bearing capacity,displacement at failure point,progressive collapse analysis of frames was simulated by the finite element method. The analytical results showed that the composite floor slabs could effectively enhance the performance of structure to prevent progressive collapse.