Study On Dynamic Response Of RC Frame Structure Under Blast Loading

With the unbalanced development of the world economy and politics and the increasingly prominent social contradictions caused by differences in cultural and religious beliefs,and people's negligence in daily activities and industrial production,explosion accidents frequently occur.The strong shock wave,high temperature and high pressure and seismic effects caused by the explosion cause various degrees of damage to the buildings around the explosion.In severe cases,the components will undergo brittle damage and even cause continuous collapse of the building.This article takes the typical frame structure as the research object,bases on the explosion theory and the finite element dynamic analysis theory,uses the numerical simulation method,uses the ANSYS/LS-DYNA finite element software to establish the simulation model of the RC frame structure under the external blast load.The dynamic response of the frame structure under different explosion distances has been studied.The main tasks are as follows:(1)Explain the typical purpose and significance of this article by analyzing the typical cases of damage caused by explosions at home and abroad.Then from the aspects of blast load,dynamic response of reinforced concrete member,dynamic response of reinforced concrete structure and continuous collapse,the research status of dynamic response of RC frame structure under blast loading is studied.(2)According to the constraints of the explosives and the relative positions of the explosion point and the structure,the blast load is classified,and the possible dynamic response and damage of the building structure under the effect of the external explosion are discussed.Through the pressure one-time curve of the ideal explosion shock wave,the propagation law of the shock wave and its main description parameters are mainly introduced.(3)Based on the explosion theory and finite element dynamic analysis theory,the finite element software ANSYS/LS-DYNA was used to numerically simulate the TNT explosion in free air.Through numerical simulation,the propagation process of air shock wave is analyzed.According to the comparison and analysis of the empirical formula of the explosion simulation and the overpressure peak value,the grid division method,the explosive and the air model,the material parameters and the ALE calculation are verified in the numerical simulation of the explosion load,which provides a basis for further study of dynamic response of RC frame structure under blast loading.(4)The finite element software ANSYS/LS-DYNA was used to establish the simulation model of the RC frame structure under the external explosion.The dynamic response of the frame structure under four different explosion distances was calculated by the fluid-solid coupling method.By comparing the stress and displacement of the whole structure and the displacement and speed of the frame column,the influence of the explosion distance on the dynamic response of the RC frame structure are studied to provide reference for the explosion-proof and anti-knock work of the building structure.