步枪弹高速侵彻弹道明胶数值分析

Numrical Analysis of High-velocity Rifle Bullet Penetrating into Ballistic Gelatin

步枪弹侵彻软组织目标过程中的翻滚和破碎效应对终点杀伤效果具有显著影响。为了揭示步枪弹侵彻明胶的运动规律和断裂机制,采用非线性动力学分析软件ANSYS-LSDYNA对步枪弹侵彻明胶的作用过程进行了数值模拟。通过与试验回收弹头比较可知,数值方法可真实再现弹头在明胶中的变形断裂行为。研究结果表明,基于刚体假设的弹头运动模型无法准确模拟发生变形的断裂弹头在明胶中的运动规律,基于节点分离的拉格朗日算法可准确模拟弹头断裂过程中铅芯的破碎飞散。弹头的断裂过程是损伤自变形后由被甲受拉伸一侧外表面向内表面和受压一侧传播的过程,辊沟和膛线划痕对弹头的断裂过程具有重要影响,初始裂痕出现在辊沟处,与被甲母线成一角度,并沿辊沟和膛线划痕传播扩展。

The rolling and fracture behaviors of rifle bullet while penetrating into soft tissue have a remarkable influence on terminal killing effects. Numerical simulation of the lead core bullets penetrating into ballstic gelatin is carried out by using ANSYS/LS-DYNA to uncover motion law of rifle bullet and fracture mechanism. The bending and fracture behaviors are in agreement with experimental results. Analysis results show that bullet motion model based on rigid body supposing could describe the motion law of deformable bullet at narrow channel. However their motion laws are different from each other after rolling observably. The Lagranian method based on tied-nodes could simulate the diaspora of lead core during bullet fracture. The fracture of lead core bullet comes from the damage accumulation that begins from roll groove on the tensile side. As the increase of bending,the fracture spreads to the inner of jacket and the compressed side. The original crack occurs on outer of jacket with a small angle between the jacket generatrix and itself and propagation along the scratch lead by grooves.