破片高速侵彻中厚背水钢板的剩余特性

为探讨破片高速侵彻中厚背水钢板的剩余特性，通过弹道实验，分析了弹体和靶板的破坏模式，比较了破片侵彻垂直和倾斜背水钢板后的瞬时余速和运动轨迹, 以及由此引起的初始冲击波的压力特性。结果表明，破片在高速侵彻下，头部产生了严重的镦粗变形，钢板背后水介质的动支撑作用不容忽视；背水钢板的破坏模式主要为剪切冲塞破坏，背弹面穿孔存在绝热剪切效应；破片穿透背水钢板初期，会产生空泡和射流，空泡大小和射流强度与破片入水初速有关，而空泡形状和射流方向则受背水钢板的倾斜角度影响；破片穿透背水钢板后，在水中的运动轨迹会发生偏转，偏转方向与破片入水初速有关；由于水介质的动支撑作用和动能耗散效应，破片穿透背水钢板后的动能损失要大于穿透背空钢板的情形；水中初始冲击波的压力特性应考虑稀疏波的影响；相同初速下，破片侵彻垂直背水钢板引起的初始冲击波的峰值压力较侵彻倾斜背水钢板要大。

Residual characteristics of moderately thick water-backed steel plates penetrated by high-velocity fragments

In this study we carried out ballistic tests to explore the residual characteristics of moderately thick water-backed steel plates penetrated by high-velocity fragments.Damage modes of projectiles as well as targets were analyzed.We compared the vertical and inclined water-backed steel plates penetrated by fragments in terms of instantaneous fragment velocities,moving trajectories and the pressure characteristics of induced incipient shockwaves.The results show that serious mushrooming deformation occur on the noses of the fragments during high-velocity penetration,and the dynamic supporting effect of water in the back of the steel plate should be considered in its examination.Damage modes of the water backed steel plates are mainly shear plugging,together with adiabatic shear effect available on the distal side of the perforation holes.In the earlier stage after the fragment perforating the water-backed steel plates,cavities and jets are produced.The cavity size and the jet intensity are both related to the initial velocities of the fragments entering the water,whereas both the cavity shape and the jet direction are affected by the inclined angle of the water-backed steel plates.After the perforation of the water-backed steelplates,the moving trajectories of the fragments will deflect,and the deflection direction is related to the initial velocities.Due to the dynamic supporting as well as the kinetic energy dissipation effects of water,the kinetic energy loss of the fragment perforating waterbacked steel plates is greater than that perforating air-backed steel plates.The influence of the rarefaction wave on the pressure characteristics of incipient shock waves should be considered.Under the condition of the same initial fragment velocity,penetration of the vertical water-backed steel plates result in incipient shock waves with higher peak pressures than those resulting from the penetration of the inclined water-backed steel plates.