步枪弹侵彻明胶靶标的数值模拟

Numerical Simulation of the Penetration of Bullet on Gelatin Target

为更好揭示步枪弹与明胶的相互作用过程及作用机理,采用显式有限元方法对侵彻过程进行了数值模拟,通过与实验数据对比验证了模型的有效性和准确性。对弹头在明胶中的受力、明胶中等效应力分布及入射攻角对明胶创伤效应的影响进行了分析。数值结果表明:在窄伤道段明胶阻力增长缓慢,随着弹头的迅速翻滚明胶阻力急剧增长,并导致弹头破碎;明胶中的最大等效应力层始终分布在瞬时空腔的内壁,随着空腔膨胀其影响区域不断扩大,并导致空腔内壁的明胶单元破坏失效;攻角的微小变化对弹头在明胶中的翻滚位置及速度衰减规律影响较大,但随着攻角的增加这种影响逐渐减弱。

The dynamic process of bullet-gelatin interaction was studied using an FEA method.The numerical modelling was set up,and the numerical results are in good agreement with the experimental results.The penetration resistance and stress distribution of bullet in gelatin and the effect of angle of attack on gelatin damage were analyzed.The results show that penetration resistance increases slowly at narrow channel,while it increases rapidly with the rapid rolling of bullet,which leads to the fracture of the bullet.The maximum stress distribution of bullet always appears around the temporary cavity,and with the expansion of cavity the elements are stretched to beyond its elastic limit,which results in the deformation and fragmentation of gelatin.Angle of incidence has a great effect on the overturning moment of bullet,but the effect decreases with the increase in angle of attack.