高速侵彻弹体表层侵蚀效应理论计算

Theoretical calculation for surface abrasion effect of projectiles penetrating in to concrete targets with a high speed

高速侵彻混凝土过程中,弹体的侵蚀效应随着撞击速度的提高而愈发显著。基于弹体表层材料热塑性失效机理,分析确定了高速侵彻过程弹体与靶体间摩擦效应和弹体材料塑性应变效应引起的温升。结合弹靶间局部作用情况,根据热传导方程和塑性功转热公式,利用Johnson-Cook本构方程,计算了弹体表层内两种效应引起的温度分布情况。利用临界温度判据,通过差分迭代法,计算得到了弹体表层材料失效厚度,分析不同工况下弹体高速侵蚀侵彻过程,得到了弹体轮廓演化情况,并与已有试验结果进行对比,验证了该模型的正确性。

The surface abrasion effect of a projectile becomes significant with increase in impact velocity during its penetrating with high speed into a concrete target. Based on the thermoplastic failure mechanism of projectile material,the friction effect between the projectile and the target in high speed penetration process and the temperature rise due to the plastic strain effect of projectile material were analyzed and determined. Combining the local action between the projectile and the target,according to heat transfer equations and the formula converting plastic work into heat,and adopting Johnson-Cook constitution equation,the temperature distribution on the projectile surface due to these two effects was calculated. Utilizing the critical temperature criterion and the difference iteration method,the failure thickness of the projectile surface＇s material was calculated,and the projectile ＇s penetration and abrasion processes under different conditions were analyzed,the projectile ＇s contour evolution was obtained. The theoretical calculation results were compared with those of the existing tests,the correctness of the proposed theory and method was verified.