弹体侵彻与贯穿有限厚度混凝土靶体的力学特性

Penetration and perforation of concrete targets with finite thickness by projectiles

为了便于研究弹体贯穿混凝土靶体的力学本质,首先假设钻地弹是刚性弹体。在水动力侵彻模型的基础上,认为在弹体的冲击下,靶体裂缝扩展到靶体背面时就开始不稳定增长。将此时刻作为贯穿的发生时刻,据此利用裂缝增长的耗能机制求得了发生贯穿时,裂缝距靶体背面的临界距离。在求解贯穿发生后的侵彻阻抗力时考虑了由于靶体背面贯穿块的运动而造成的弹体相对速度的降低。计算表明,弹体端部侵入靶体与贯穿发生后2阶段弹体的减加速度变化剧烈,而弹体端部完全进入靶体后至发生贯穿阶段,弹体的减加速度变化相对较小。将计算结果与前人实验做了对比,验证了结果的可信性。

Projectiles were regarded as rigid ones to simplify the mechanics principle of the perforation for concrete targets. According to the hydrodynamics model, the cracks were considered to increase astatically when they expanded to the back of the target under the impact of a projectile. This time was defined as the moment that the perforating action began. The critical distance to the back of the target was deduced by the energy dissipation mechanism for crack extension. After the cracks arrived at the backs of the targets, the penetration resistance was calculated by considering the relative velocity between the projectile and the plug. The calculated result indicates that the deceleration changes remarkably when the warhead is intruding the target and after the perforating action begins, whereas the deceleration changes weakly between the above two stages. Comparison between the calculated results and the existent experimental results shows the calculated results are credible.