SPH耦合FEM模拟弹丸撞击对表面形貌的影响

为消除有限元法(finite element method, FEM)处理切屑分离及大变形问题的局限,使用光滑粒子流体动力学法(smooth particle hydrodynamics, SPH)耦合FEM模拟此类问题。工件使用SPH建模,弹丸使用FEM建模,二者通过接触算法实现耦合，通过仿真实验研究锐边弹丸在不同入射条件下撞击工件时,弹丸的翻转效应对工件表面弹坑深度、切屑堆积高度的影响。结果表明:当前倾角较大时,弹丸向前翻转,对工件表面产生碾压作用,形成尖锐的弹坑,切屑堆积在弹坑前部边缘不与工件分离;当前倾角较小时,弹丸向后翻转,对工件表面产生铲削作用,切屑与工件分离,弹坑横截面光滑而平缓。通过与相关实验及理论数据的比较,验证了仿真模型及结果的正确性,为锐边弹丸侵蚀工件表面的仿真研究提供新的手段。

Numerical simulations of a particle impacting to affect the surface morphology by SPH coupled FEM

The smoothed particle hydrodynamics (SPH) method coupled FEM was applied to eliminate the limitations of finite element method (FEM) dealing with the chip separation and large deformation of the work piece. The SPH particles were used to model the work piece and the FEM was applied to discrete the angular particle, which were coupled by using the contact algorithm. The influence of particle rotating effects on the crater depths and chips pile-up heights was studied under different simulation incidence conditions. The results showed that the particle would rotate forward when its rake angle bacame large enough. The angular crater would be formed and chips would pile up at the edge of the crater without separating from the work piece. On the other hand, the particle would rotate backward when its rake angle was small. A shallow and smoothed crater would be formed and chips would separate from the work piece. The simulation model and results were validated by the existing theoretical and experimental data, which could provide an effective simulation research method to study angular particle erosion.