耦合方法在超高速碰撞数值模拟中的应用

Application of the Coupling Method in Simulating the Hypervelocity Impact

相比于传统的数值方法,无网格光滑粒子法(SPH:Smoothed Particle Hydrody-namics)更适合模拟超高速碰撞问题,它能够清晰地模拟材料界面,并且能够克服中网格大变形导致的数值不稳定。然而在SPH方法中,为了得到t时刻一个节点上的物理量,需要先找出与它相互作用的临近节点,导致计算速度很慢,计算所需的时间远远大于有限元方法所需的时间。采用SPH与Lagrange法相耦合的方法对3D超高速碰撞过程进行了模拟研究。计算结果表明:SPH与Lagrange法耦合方法的计算结果与SPH计算结果精度接近,并且能够大大地节省计算时间。

Compared to the traditional numerical methods, meshless SPH method is more suitable to simulate the hyperveloeity impact in that it can simulate the material interface clearly and overcome the numerical instability due to the large mesh deformation in the Lagrange method. In SPH, in order to get the physical value of one nodal at time t, it is firstly required to find the neighboring nodes interacting with it, so the calculation speed is slower and the calculation time is longer than that of the FEM. This paper adopts the coupling method of SPH and Lagrange to simulate the 3D hyperveloeity impact problem. The results show that the coupling method can save largely time while keep the accuracy approximately to that of SPH.