冰弹超高速撞击铝合金靶板的损伤形貌分析

Analysis of the Al-alloy plate injury appearance under ice projectiles hypervelocity impacts

针对铝合金靶板受冰弹丸超高速撞击时所产生的类8字形和类椭圆形损伤形貌,采用试验与理论分析相结合的方法,利用弹性力学理论对损伤形貌的生成机理进行分析研究。以靶板撞击点为原点建立力学模型,分析在弹丸撞击靶板瞬间,靶板撞击点处各方向上的应力分布情况。分析结果表明:在靶板撞击点处各方向上的应力分布不均匀,呈类8字形分布;当撞击产生的应力超过材料的屈服极限后材料开始塑性变形,从而导致靶板产生类8字形的鼓包;当撞击产生的应力超过材料的断裂极限后材料开始撕裂,撕裂后的损伤区域总体上呈现类椭圆形。这说明靶板撞击区的类8字形和类椭圆形损伤形貌是由材料的弹性效应导致的。

Aiming at the defeatures of 8-shape or oval-shape occurred in the target plate of aluminium alloy under ice projectiles hypervelocity impacts,the mechanism of production for producing defeature is analyzed by applying different methods which combined experimental results and elasticity theory.The mechanics model is built up by choosing the impact point as the coordinate origin,the stress distribution at the moment of impact is analyzed.When the stress is greater than the yielding limit of aluminium alloy,the plastic deformation will be produced and the convex zone defeature of 8-shape will occur on the plate surface;when the stress is greater than the fracture limit of aluminium alloy,the fracture will be produced,and then,the oval defeature will occur on the surface of the target plate.According to above discussions,it can be concluded that the material's buoyancy effect is responsible for the 8-shape and the oval defeatures of the zone target plate.