Numerical simulation of material surface damage by high speed liquid-solid impact

The numerical model for high speed liquid-solid impact considering fluid-structure interaction coupling effect was developed based on smoothed particle hydrodynamics (SPH) and finite element method (FEM). The damage of polymethylmethacrylate (PMMA), caused by a single droplet and a jet impact with a radius of 2 mm and a speed of 1 000 m/s, was analyzed. The numerical results show that the distortion and interior pressure of the droplet and the jet are almost the same at the beginning of impact. The maximum pressure inside the droplet occurs at 0.20 μs after impact, and the maximum equivalent stress inside solid is only 104 MPa which can not lead to material damage. It is mainly the inclined jet which has a speed of 2 925 m/s and occurs at 0.32 μs that causes the material surface damage. The initial damage by impact is located in a circular region whose center is the impact position. The material surface damage predicted by the numerical simulation shows good agreement with the experimental data of Brunton.