刚性弹体撞击蜂窝结构高过载特性

Overload Characteristics of Rigid Projectile Impacting Honeycomb Structures at High Velocities

为考核武器关键部件在高过载环境下的可靠性,提出一种基于刚性弹体撞击蜂窝结构的新型高过载环境模拟技术。通过轻气炮弹道实验,研究弹体加速度、速度和位移响应规律及蜂窝结构在冲击过程中的力学行为;比较不同撞击速度条件下,弹体高速撞击蜂窝结构过程中过载响应时间历程的差异。研究结果表明:刚性弹体高速撞击造成的蜂窝结构压溃是高度局部化的力学行为,压溃首先发生在蜂窝结构顶端,并随弹体运动由顶端向底端传播;弹体对蜂窝结构冲击压缩过程可分为初始冲击、稳态压缩、密实压缩3个阶段,可分别对应弹体的加速度、速度、位移曲线中相应的响应特征;初始冲击阶段的速度曲线呈明显的阶梯状下降形态,为应力波在弹体中周期性传播导致;3发实验的初始冲击阶段过载峰值相差不大,稳态区持续时间随弹体撞击速度的增加而减小,密实区过载峰值随弹体撞击速度的增加而增加。

In order to evaluate the reliability of critical weapon components in high overload environments,a new technology of high overload environment simulation based on the rigid projectile impacting the honeycomb structure was proposed.The acceleration,velocity,displacement response characteristics and dynamic behaviors were studied with the light gas gun experiment.The difference of overload response time histories in the process of the projectile impacting the honeycomb structure under different high impact velocities was analyzed.The results showed that:crushing is a highly localized mechanical behavior,which firstly happened at the top of the honeycomb structure and then spread to the bottom as the projective moved;the compression process of the honeycomb structure subjected to projectile impact can be divided into three stages:initial impact,steady compression and compression to densification,which corresponds to the response characteristics of acceleration,velocity and displacement curves of the projectile;the velocity curve of initial impact stage showed an obvious ladder-shaped decline,resulting from the periodic traveling of stress waves in the projectile;all deceleration curves obtained from the three experiments had a similar peak at the initial stage of each experiment;the lasting time of the steady compression stage decreased with the increase of the initial velocity of the projectile,but the overload peak of the densification stage showed an opposite trend.