Study On Damage Effect Of Column In Frame Shear Wall Structure Under Contact Explosion

In the prevention and control of major urban disasters,explosion accidents are generally divided into three situations: one is accidental explosion accident,the second is terrorist bomb attack by terrorists,and the third is the attack of precision weapons on important urban structures and buildings,so that the structures directly cause explosion.The occurrence of the accident will cause a chain reaction,resulting in huge casualties and property losses,which will have a great negative impact on the society.However,there are many frame shear wall structure buildings in cities,so it is particularly important to study the structural damage and dynamic response of frame shear wall structure under accidental explosion impact load.In this paper,the damage effect test and numerical simulation of frame shear wall structure model under explosion are studied according to the needs.The main work is as follows:(1)Taking the actual situation of the site as the basic condition,through the relationship between the original model and the reduced scale model,a 1:5 two-story five four span frame shear wall structure model is designed.Combined with the similarity theory,the concrete strength,reinforcement size and reinforcement ratio are calculated,and the actual material mechanics parameters of concrete and reinforcement are measured through the actual test.(2)Four groups of contact explosion tests under different working conditions were carried out.According to the model test results,the transmission law of explosion shock wave is analyzed,and the strain response of reinforcement in concrete,the strain response of concrete and the vibration acceleration of particles at different positions and different explosion equivalent are studied.(3)The structural damage appearance characteristics of independent column explosion test and integral model explosion test are analyzed,and the explosion damage degree and damage factors are studied.It is analyzed that,in the specific concrete low strength test model,150 g emulsion explosive will completely damage the surface of the contact member of the frame shear structure.(4)Through the numerical simulation of the model test,the model building of the actual model test is modeled,and the finite element analysis software LS-DYNA is used to simulate the explosion condition of the test model in the actual situation,analyze its dynamic response and damage characteristics under the explosion impact,and compare with the analysis results of the actual model test,and the two are in good agreement.(5)The finite element analysis of the original reference model is carried out.Combined with the actual situation,the numerical simulation of the original reference model under explosion impact is carried out.Through the simulation under three different explosion conditions,the dynamic response characteristics under certain conditions and the overall damage characteristics of the model are determined.From the test and simulation results,it can be seen that the single point initiation has little impact on the integrity of the building,and will not cause the continuous instability and collapse of the building under specific circumstances.Then the reasonable and effective protective measures are put forward according to the experimental and numerical simulation.