基于OTM方法的超高速碰撞问题数值模拟

Compared with the SPH method, the optimal transportation meshfree method (OTM) can effectively overcome the non-conservation of energy, and completely avoid the tensile instability and the zero energy mode. Numerical simulations of hypervelocity impact of aluminum alloy plates by aluminum spherical projectile were presented using the OTM method. The Johnson-Cook constitutive model and the Mie-Grüneisen state equation were employed to describe the dynamic response of aluminum subjected to high strain rates, high pressures and high temperatures. In the simulation of the impact on single plate, the OTM's numerical results of crater diameters, the width and the length of debris cloud and the core debris cloud's shape and distribution were in good agreement with the experimental results. Furthermore, the hypervelocity impact on double plates was also simulated by the OTM method, and the results indicated that the morphology characteristics of debris cloud fitted the experimental results well, and the error of secondary debris cloud's length between numerical and experimental results was only 2.6%. All the numerical results prove that the OTM method is more suitable for the simulation of hypervelocity impact.