Simulation Of The Propagation Of Explosion Wave In Complex Urban Environment And Rapid Assess The Damagement Of Buildings

With the development of society and economy,the range of city is becoming larger and larger.The commercial and pedestrian districts in cities is becoming the targets of bombing attacks.At present,there are few simulations of large-scale urban block explosions in China.Because of the large scale of urban buildings,the number of air grids for the three-dimensional numerical model is large,and the existing calculation level is difficult to meet the requirements of simulation.In addition,the selection of appropriate air grid size is very important to ensure the simulation accuracy and rapid damage assessment of buildings.Based on this,the main work and research results of this paper include the following three aspects:(1)Determination of the most suitable air grid size and verification of the modelFirstly,the air grid size of free air field and reflected air field under 1 kg TNT equivalent is analyzed.The optimum air grid size is 1.4 m/kg 1/3-6.0 m/kg 1/3.Then,according to Hopkinson's proportional law,the optimum air grid size under different TNT equivalents is obtained.Finally,the ROSE ideal city experiment is simulated by the "step-by-step" simulation method,which verifies the correctness of the most suitable air grid size to simulate urban complex environment explosion.(2)Simulation of Blast Wave Propagation in Urban Complex EnvironmentFirstly,the rapid method of city model building is determined.Then,the "step-bystep " simulation method is used to simulate the explosion of two buildings within 250 m and 200 m of a block in Tianjin,and the explosion data obtained from two cases are verified.Finally,some laws of explosion wave propagation in urban environment are obtained by analyzing the explosion data of some measuring points.(3)Rapid damage assessment of buildingsFirstly,based on the original damage criterion,the damage curves of doors and windows,infilled walls,reinforced concrete slabs and reinforced concrete columns suitable for concrete structures are proposed.Then,according to the simulation data of two urban explosion cases,the damage assessment of the whole and individual buildings based on components is carried out.Finally,the damage ranges along the plane and along the height of single buildings are given.