新粒子生成手法と粒子縮合手法を取り入れた改良SPH法による固体—固体超高速衝突現象の数値解析

抄録

In the numerical simulation of hypervelocity impacts (HVIs) by means of a conventional SPH method, the loss of interactions among the particles causes numerical fractures. To prevent the numerical fractures, a 2-dimensional SPH method is improved using new particle generation and particle reducing techniques. In the new particle generation technique, new particles are generated in the case when the area with no particles or the distance between the adjacent particles exceeds a certain value. In the particle reducing technique, which is used to avoid the overabundance of particles, two particles approaching each other are combined to one when the distance between them attains a certain value. The perpendicular HVIs of a polyethylene projectile on an aluminum plate target are simulated numerically. Through the numerical results, it is shown that the improved SPH method can prevent effectively the numerical fractures without the overabundance of particles. The responses of oblique HVIs are also shown.