钝头弹高速斜侵彻中厚背水金属靶板的机理研究

为探讨高速钝头弹斜侵彻中厚背水金属靶板的机理，根据不同的受力状态及耗能机制，结合中厚背水靶板抗高速斜侵彻特点，通过厚度等效，将斜侵彻转化为相应的正侵彻。然后，将整个侵彻过程分为压缩镦粗、剪切压缩和剪切扰动三个阶段。基于三阶段侵彻机制，建立了钝头弹高速斜穿甲中厚背水金属靶板后的瞬时余速计算模型，并讨论了该计算模型的局限性。采用该模型计算了3.3 g立方体弹丸斜穿甲5 mm背水钢板后的瞬时余速，理论计算值与试验结果及相应的仿真计算值均吻合较好。由于该模型考虑了靶后水介质的动支撑作用及动能耗散等效应，在一定的适用范围内，能对钝头弹高速斜侵彻中厚背水金属靶板的瞬时余速进行合理地预测，具有一定的理论价值和工程应用价值。

MECHANISMS OF MODERATELY THICK WATER-BACKED METAL PLATES OBLIQUELY PENETRATED BY HIGH-VELOCITY BLUNT-NOSED PROJECTILES

To explore the mechanisms of moderately thick water-backed metal plates obliquely penetrated by high-velocity blunt-nosed projectiles, the oblique penetration was converted to corresponding perpendicular penetration through thickness equivalence. The conversion was conducted according to different mechanical states and energy-dissipative mechanisms during the oblique penetrating process together with the high-velocity oblique penetration-resistant characteristics of moderately thick water-backed metal plates. Then, the whole process was divided into three consecutive phases, i.e., the compression & mushrooming phase, shearing & compression phase and shearing & intruding phase. Based on the three-phase penetration mechanism, an analytical model was established to calculate instantaneous residual velocities of the blunt-nosed projectiles obliquely perforating moderately thick water-backed metal plates. Moreover, the limitations of the present model were discussed. By adopting the present model, the instantaneous residual velocities of 3.3g cubic projectiles obliquely penetrating 5mm-thick water-backed steel plates have been calculated. Good levels of agreement were obtained between the theoretical values and experimental results as well as corresponding numerical results. Considering several phenomena, such as the dynamic supporting action and kinetic energy dissipation effort of the water medium behind the target, the three-phase model can be employed to reasonably predict, in the valid regime, the instantaneous residual velocities of the blunt-nosed projectiles obliquely perforating moderately thick water-backed metal plates, and therefore, has theoretical and engineering application values.