The Influence Of Frame Structure Local Column Failure On Overall Performance

The assurance of safety of structure is a primary structural design objective, because of the uncertainty of accidental load, it generally is out of consideration when designing the building structure. However, from a large number of the project cases of structure collapse in recent years, it can be seen that in service period building structure may possibly be subjected to accidental load that hasn't been considered in the original design, such loads can make partial structure members damage and cause the partial or overall collapse of structure. Once structure continuous collapse occurs, it will cause a serious loss of life and property, so how to evaluate the resisting progressive collapses ability when carries on the structural design has been drawing more and more concern. At present, how to enhance structure progressive collapse resistance has been carried out interrelated research in Europe and the United States and other countries, and a series of codes to resist progressive collapse have been proposed, but research in this realm in China is still very insufficient, that still has an enormous amount of work to be done.This paper reviews the development history of research of structure progressive collapse, summarizes and compares the foreign current progressive collapse resistance analytical methods, at the same time, on the basis of the progressive collapse resistance analysis steps specified by American GSA and DoD codes, this paper also raises an improved method of analyzing the ability of structure resistance to progressive collapse using dismantled component method, and the analysis process according with this paper is formulated. This paper also probes into possibility and analysis steps of using the general FEM software ANSYS to analyze structure progressive collapse resistance after local components are destroyed, builds the finite element model for a seven-story RC frame structure, and uses linear static and nonlinear dynamic analysis by ANSYS and SAP2000 to estimate the ability of structure resistance to progressive collapse in various typical local component damage working conditions, such as the damage of long side column, short side column, corner column, interior column and so on, so as to understand internal force redistribution path after frame column is failure, master the rule of progressive collapse and provide the theory basis for strengthening structure and component and preventing progressive collapse. Based on the above research, the paper provides strategy for avoiding progressive collapse caused by the damage of local component from the angle of controlling the happenstance of accidental events, preventing local structural damage and ensuring reasonable structure design.