EFP侵彻钢靶板过程的光滑粒子法数值模拟研究

针对爆炸成形弹丸（EFP）的成型及侵彻钢结构靶板的问题运用无网格数值方法 SPH法进行了数值模拟研究。计算中采用完全变光滑长度SPH方法解决模拟爆炸过程中密度等物理参量变化梯度剧烈的问题,利用Ott-Schnetter提出的修正SPH方法处理在求解多介质大密度差问题时遇到的数值不稳定性问题,运用含损伤的Johnson-Cook本构模型处理钢板在冲击载荷下的变形与损伤问题;结果分析了弹丸头部特定节点处的速度变化历程,同时分析了不同药罩厚度对弹丸头部速度及对靶板侵彻过程的影响及不同尺寸的靶板在弹丸侵彻作用下的破坏形式,结果符合弹丸侵彻物理规律,表明该方法适合模拟爆炸与冲击等大变形破坏损伤问题。

Numerical Simulation of Steel Target Penetration by Explosively Formed Projectile with Smoothed Particle Method

The processes of forming of the EFP and the steel target penetration by it were simulated by SPH method. SPH method with fully variable smoothing lengths was used to deal with large density gradient and large smoothing length gradient problems. The modified 0tt-Schnetter SPH method was used to cope with the computational instability in the large density gradient problems between different materials. The John- son-Cook constitutive model including damage model was used to cope with the deformation and damage of steel target under impact. Then the process of a steel target penetrated by EFP was simulated and the chan- ging courses of velocity on some special points of projectile head were analyzed. The relationship between the velocity of projectile head and the sizes of cover thickness and the penetrating styles influenced by the size of cover thickness and the target were also analyzed. The result is in good agreement with the physical principle. It shows that this method can deal well with the multi-material and large deformation problems such as the detonation and impact problem.