The Dynamic Response Of An RC Frame Considering The Contribution Of Slab In Progressive Collapse

The progressive collapse of structure refers to the failure of local structure caused by accidental load and the failure of adjacent members caused by an unbalanced force.In recent years,terrorist attacks have been rampant,and the progressive collapse of buildings has attracted the attentio n of the engineering community and has become a hot spot.At present,there are three kinds of engineering design methods for progressive collapse: conceptual design method,alternate path method and tensile strength method,among which the method of alternate path method is the most commonly used methods.In this paper,the nonlinear dynamic analysis method is used to study the dynamic response of a reinforced concrete frame structure under corner column failure.In this paper,the numerical analysis platform of universal finite element software ABAQUS is used to establish the frame that simulates the progressive collapse of concrete numerical model.The progressive collapse performance of the model designed in this paper is analyzed.The main contents are as follows.1.In this paper,a simplified progressive collapse analysis model is adopted and the dynamic equations are listed according to the characteristics of the model,which synthesizes the latest progress in the research of the theory of progressive collapse of structures at home and abroad in recent years.The resistance mechanism of progressive collapse,beam mechanism and cautionary mechanism and the enhancement of slab in the progressive collapse resista nce to the frame,are discussed in this paper.2.When the method of removing components is adopted in the progressive collapse analysis,according to the stipulation of DOD2013 and GSA2013,which is the standard code to study the progressive collapse at present,"the time of column removal is less than 1/10 of the natural vibration period of the remaining structure",In this paper,the nonlinear dynamic response of different component removal methodis used,the dynamic response of residual structure under different time of corner column removal is studied,According to the relationship between the column removal time and the dynamic response of the residual structure,the displacement response spectrum curve is obtained,which is divided into three stages: pulse stage,dynamic stage and quasi-static stage,and the influence of the column removal time on the dynamic response of the residual structure is compared.3.In the past,the initial state of the structure was assumed to be zero when analyzing the progressive collapse of the structure,which was inconsistent with the non-zero initial state of the progressive collapse of the structure caused by the sudden situation such as explosion and impact.The failure of structural columns caused by accidental loads such as impact is very similar to that of non-zero initial velocity and initial displacement applied vertically at the top of structural columns.These non-zero initial states affect the dynamic response of the structure.In this paper,the influence of initial state on the dynamic respose of residual structure under progressive collapse is studied by using nolinear dynamic column removing method.At the same time,the dynamic response of the structure considering the Rayleigh damping of the material is studied,and the effect on the dynamic response of the structure is obtained by comparing the dynamic response of the structure with the Rayleigh damping of the material without considering the Rayleigh damping of the material.