光滑粒子流体动力学-有限元法接触算法研究

Research on Contact Algorithm between Smoothed Particle Hydrodynamics and Finite Element Method

耦合光滑粒子流体动力学(SPH)方法和有限元法(FEM),是研究冲击动力学问题的一种有效途径。为解决SPH粒子和有限单元间的接触问题,提出了SPH-FEM接触算法。该算法是在有限元节点处设置背景粒子,采用SPH接触算法的思想,计算施加在SPH粒子和有限元节点上的接触力,并且以外力的形式分别加入到SPH动量方程和有限元动力学方程中。利用SPH-FEM接触算法,对两杆撞击以及圆柱形钢弹正冲击钢板发生的冲塞破坏过程进行了三维数值模拟,靶板采用含损伤的Johnson-Cook模型和Grüneisen状态方程,模拟结果与实验结果吻合较好。

The coupling between smoothed particle hydrodynamics（SPH） and finite element method（FEM） is an effective approach for the simulation of impact dynamics.An alternative algorithm for the treatment of contact problem between SPH particles and finite elements was employed.Background particles were assigned in the position of finite element nodes,and the contact forces on SPH particles and finite element nodes were calculated with the same approach as SPH particles to particle contact algorithm.The contact force was added to the momentum equation for SPH and dynamic equation for FEM respectively.Using the SPH-FEM contact algorithm,the axial impact between two bars and the perforation of a cylindrical steel projectile impacting a plate target were simulated,where the Johnson-Cook material model with damage effect and Grüneisen equation of state were employed.The computed results showed good agreement with the experimental data.