超高速碰撞下相变效应的交错网格物质点法研究

超高速碰撞下的结构毁伤过程常伴随材料相变、断裂失效及碎片云的产生与演化，其所具有的压力强间断、材料非线性等几何大变形等问题给数值模拟带来了困难。交错网格物质点法SGMP通过背景网格格心积分消除了物质点法MPM跨网格误差，是模拟固体冲击爆炸等极端大变形与材料破坏问题的一种有效数值分析方法。本文将含金属相变的GRAY状态方程及含非线性内聚力断裂的Johnson-Cook修正金属模型引入SGMP中，模拟超高速碰撞单层、多层靶板问题。结果表明，SGMP和修正金属模型可以很好地模拟超高速碰撞问题中的碎片云形貌特征和相变效应。

The staggered grid material point method (SGMP) simulation of phase transformation in hyper-velocity impact

The structural damage process under hyper-velocity impact is always accompanied by material phase transformation, fracture and formation of debris cloud.Its numerical simulation is difficult due to the high pressure discontinuity, material nonlinearity and large geometric deformation.The staggered grid material point method (SGMP) eliminates the cross-grid error of material point method (MPM) through the background grid center integral.Therefore SGMP is an effective numerical analysis method for simulating extreme large deformation and material failure problems such as solid shock and explosion.In this paper, GRAY equation of state and Johnson-Cook modified metal model are introduced into SGMP to simulate the hyper-velocity impact with single-layer and multilayer targets.The results show that SGMP with the modified metal model can simulate the morphology and phase transition effect of debris cloud in hyper-velocity impact.