挡墙对冲击波削弱作用的数值分析

Numerical Simulation of the Weakening Effect of Retaining Wall on Shock Wave

基于任意拉格朗日-欧拉(Arbitrary Lagrange-Euler,ALE)算法,采用有限元软件AutoDyn对TNT炸药地面起爆后,爆炸冲击波遇到挡墙时的传播及挡墙对冲击波的削弱作用进行了三维数值分析.分析了爆炸冲击波遇到挡墙后的反射、绕射及绕射后汇聚的全过程,并通过改变炸药比距离、挡墙尺寸分析了其对冲击波的削弱作用.结果表明:在挡墙作用下,挡墙背面冲击波峰值到达时间将被延长,相对于自由空气中挡墙背面的压力峰值将大大减小;在挡墙高度一定的情况下,其宽度越宽,对冲击波的削弱作用越强,但当挡墙高宽比H/B≤0.25时,挡墙宽度的影响将会很小.

Based on arbitrary lagrange-euler（ALE） algorithm,using finite element software AutoDyn,the propagation was analyzed when the explosion shock wave met the retaining wall after the TNT detonated on the sand ground.Weakening of shock wave subjected to different sizes of wall was studied.The results show that relative to free air,the arrival time of the overpressure behind the wall is delayed and the value is greatly reduced.When the height of the wall keeps constant,the weakening effect is increased with the width of the wall until the aspect ratio H/B≤0.25.