The Mechanical Behavior Analysis Of Progressive Collapse Resistance On Steel Frame Structure

With the rapid development of economy,the building structure also put forward to higher requirements,in which the steel structure is widely used in large span and high-rise buildings.Structural members in the accidental load damage,often lead to the progressive collapse,the structure in the event of collapse,it will cause extremely serious consequences,coupled with frequent attacks in recent years,public infrastructure has become the primary target of terrorist attacks,therefore,the mechanical behavior analysis of progressive collapse resistance on steel frame structure has important theoretical and engineering value.This paper introduces the three codes of Anglo-American and European standards,and compares the load combination and judge rule,then combined with China’s relevant codes,a 9-story,6x5 bay-steel frame structure model was constructed by using SAP2000 finite element software,the vertical two-dimensional steel frame structure selected from the space steel frame structure and the space steel frame structure were respectively analysised by the method of alternate load path(APM method)to do static procedure and dynamic procedure.Finally,compared the results of the vertical two-dimensional steel frame structure and the space steel frame structure.The conclusions are as follows:(1)In the vertical analysis of the two-dimensional steel frame structure,the bottom story of the damage-bay’s beam member is damaged in the first place when remove the middle column,and the second storey layer of the damage-bay’s beam member is damaged in the first place when remove the side column,and the order of damage was not obvious.(2)The Space steel frame structure and the vertical steel frame structure In the static analysis need to consider the dynamic magnification factor a,and the dynamic magnification factor a influenced by the initial load combination magnitude and the removal working conditions.(3)In the damage-bay Pushdown analysis,the damage-bay’s beam member or the damage-bay’s column member will be destroyed when the space steel frame structure collapses,and the damage-bay’s beam structure will be destroyed when the vertical two-dimensional steel frame structure collapses.(4)The nonlinear dynamic analysis uses the loading method considering the initial state of the structure,for the dynamic effect of the remaining structure after removal of the column,the vertical two-dimensional steel frame structure is larger than the space steel frame structure.Changing the instantaneous loading time will influence dynamic effect both of the vertical two-dimensional steel frame structure and the space steel frame structure,and the influence is much bigger to the two-dimensional steel frame structure.(5)Comparing the nonlinear static procedure and the nonlinear dynamic procedure of the two-dimensional steel frame structure and the space steel frame structure,the internal distribution path of the two structures after the removal of the column is the same,but the internal force redistribution path of space steel frame structure is more.