Numerical Analysis Of Continuous Collapse Of Concrete Frame Structure Under Explosive

Currently, the studies about the design of building structure in the progressive collapse prevention cannot fully meet the design requirements, in practical analysis about the progressive collapse of the structure, considering of the reflected shock wave from the rigid ground and the initial state of the residual structures and other factors can increase the accuracy of analysis. It has a certain guiding role for the antiknock design of reinforced concrete frame structure and the progressive collapse prevention design of structure.This paper based on the theory of nonlinear dynamic analysis method and using PKPM software to get reinforced information of concrete frame witch has seismic intensity of6degrees by an alternate path method, using the finite element software ABAQUS/Explicit establish a common frame structure of the three-dimensional finite element model on the basis of experiment and the existing research; The primary work includes:(1)Studying the relevant of the rate, and influence about the reflection of shock wave from the rigid ground change with the distance(R) between the explosion center and measure point.(2)Compare under different distance and explosive yield, the damage of frame structure and a layer of beam-column joints of concrete damage, the equivalent analysis of different distances and different impact on the frame structure of continuous collapsed under various working conditions.(3)Studying the remaining components of the initial speed of concrete frame structure the influence of continuous collapsed. According to the empirical formula of concrete damage, considering the velocity of residual component before and after the concrete stress and strain data, put forward the remaining (beams, columns) artifacts approximate calculation formula of the concrete elastic modulus damage.Some conclusions are given as:(1) Drawing on the experience of previous mesh, combined with hourglass phenomenon judgment conditions to select the grid size, so meshing is more reasonable when gridded sharing.(2) It should take full account of the structure of the internal force of the shock wave caused by the additional effect of reflection on the role of a rigid floor when doing proof and anti-progressive collapse design.(3) In considering the initial velocity of the remaining members after significant structural damage intensified. In particular beam-column joints and column conditions underlying each end node column are destroyed faster into the state. Therefore, We should fully consider the initial state of the remaining members may improve the accuracy and security analysis when we doing engineering design.(4) In this paper, the basis of generic anti-GSA progressive collapse analysis method (alternate load path method), considering the rigidity of the ground reflection effect and residual components of the initial velocity of the impact of structural progressive collapse, It can improve the accuracy of analysis GS A method.