高强度钢壳体战斗部爆炸破碎无网格法数值仿真

Numerical simulation on fragmentation of high strength steel warhead shell driven by explosion based on grid-free method

为研究高强度钢壳体战斗部破碎过程及质量和速度分布特征的数值仿真方法,以"飞鱼"导弹战斗部为例,壳体采用光滑粒子动力学(Smoothed Particle Hydrodynamics,SPH)方法进行战斗部爆炸驱动壳体膨胀及破碎过程的数值仿真,炸药采用Lagrange单元,壳体和端盖采用SPH单元,进行Lagrange与SPH算法耦合实现炸药爆炸驱动壳体破碎。通过选取不同尺寸的SPH粒子分别进行计算,获得破片数随SPH粒子尺寸变化的规律以及战斗部爆炸形成破片的质量与速度分布特征,并对比传统Mott公式和Gurney公式的工程计算结果,得到SPH粒子尺寸为0.25 cm时所建立的仿真模型与工程计算较为吻合。采用经过工程计算验证过的模型进行仿真计算,获得爆炸载荷作用下战斗部壳体各段与端盖的质量和速度分布规律、每个破片的质量与速度分布以及各段形成破片的飞散方向与飞散角。

The numerical simulation method of the crushing process,and the mass and speed distribution characteristics of high strength steel warhead shell after explosion was studied. Taking'Exocet'missile warhead for example,the expansion and fragmentation of warhead shell driven by explosion were simulated with Smoothed Particle Hydrodynamics(SPH)algorithm.During modeling process,the explosive was plotted with Lagrange elements,the shell and end cover with SPH elements,LagrangeSPH was coupled to achieve the fragmentation of warhead shell driven by explosion. For the simulation model,different sizes of SHP particles were applied to reveal the variation laws of the amount of fragments with the size of SPH particles and the mass and speed distribution characteristics of the fragments generated by explosion. And comparing numerical simulation results with engineering analysis calculated by traditional Mott and Gurney formulas,numerical simulation with SPH particles in 0.25 cm was consistent with engineering analysis. The verified model was simulated,mass and speed distribution characteristics of the shell and bottom of the warhead after explosion were obtained,as well as mass and speed of per fragment and dispersing direction and angle of fragments for every part.