超空泡射弹结构响应的流固耦合仿真研究

摘要

先利用Logvinovich独立膨胀原理提出了流体域的一种简化计算模型,然后通过LS-DYNA有限元软件对存在尾拍的超空泡射弹的结构响应进行流固耦合数值计算,并比较分析了弹体长细比对结构响应的影响.计算结果表明:第一主应力、第三主应力、最大剪切应力和Von Mises等效应力近于同步变化；在射弹运动的初始阶段,各应力值和弯曲变形达到最大；弹体中部的应力最大且弯曲变形最严重.当弹体的长细比增加时,速度响应的频率变小,应力最大值的变化较复杂,应分段考虑,同时弯曲变形程度明显增加.%Based on the principle of Logvinovich of the cavity sections expansion, a simple simulation model of the fluid region was presented. The structural response of the projectiles which underwent tail slapping was calculated through fluid-structure interaction (FSI) method using the software LS-DYNA. And the relations between the slenderness ratio of the projectile and the structural responses were investigated. The simulated results show that maximum principal stress, minimum principal stress, maximum shear stress and Von Mises stress vary almost synchronously, these stresses and bending deformation grow to their maximum in the initial period of projectile moving, and the maximums of them locate on the middle part of the body. Additionally, as the slenderness ratio of the projectile increases, the frequency of the velocity response decreases, the bending deformation becomes larger, and the variation of the stress maximums should be considered on divided segments.