超空泡射弹水下侵彻靶板三相耦合数值模拟

超空泡射弹侵彻问题的实质是特殊水下结构受到高速冲击载荷作用下的动态响应。对12.7 mm口径超空泡射弹侵彻典型水下目标壳体的毁伤效果开展研究,基于LS-DYNA有限元分析软件建立水环境中超空泡射弹垂直侵彻曲面靶板的等效模型,探讨射弹侵彻过程中动能侵彻和气泡溃灭对靶板联合毁伤效果,获得了靶板在各阶段的应力变化和结构变形规律。结果表明:侵彻靶板前,射弹着靶速度为200 m/s时的头部表面水介质压力峰值达768 N,靶板表面有明显下凹变形;侵彻靶板时,伴随着射弹动能侵彻和气泡溃灭冲击,水介质造成的影响不足动能侵彻的2%;侵彻靶板后,在靶板正面形成峰值速度为42 m/s的水射流进一步作用于破口;靶板整体弯曲变形,在200~300 m/s范围内,随着射弹着靶速度的增加,靶板弯曲形变量减小;靶板局部发生延性穿孔,射弹在水环境中具有更好的破口效果,射弹速度变化对破口尺寸影响不大。

Three-Phase Coupling Numerical Simulation of Underwater Penetration of Supercavitating Projectile into Target Plate

The essence of supercavitating projectile penetration is the dynamic response of a special underwater structure subjected to high-speed impact load.In this paper,the damage effect of 12.7 mm supercavitating projectile penetrating typical underwater target shell is studied.Based on LS-DYNA finite element analysis software,the equivalent model of supercavitating projectile penetrating into curved surface target vertically in water environment is established.The combined damage effect of kinetic energy penetration and bubble collapse on target plate during penetration is simulated,and the stress variation and structural deformation law of target plate at different stages are obtained.The results show that the peak pressure of water medium on the head surface reaches 768 N when the velocity of projectile is 200 m/s before penetrating the target,and the surface of the target exhibits obvious concave deformation;with projectile kinetic energy penetration and bubble collapse impact during penetrating process,the impact effect of water medium is less than 2%of that by kinetic energy penetration.After penetrating the target,a water jet with a peak velocity of 42 m/s is formed on the front of the target and further acts on the break.The overall bending deformation of the target plate occurs.In the range of 200 m/s to 300 m/s,the bending deformation decreases with the increase of projectile impact velocity.Ductile perforation occurs locally on the target plate,and the projectile has better perforation effect in water environment.The change of projectile velocity has little effect on the size of the perforation.