泡沫子弹冲击下预制圆孔 Q235 钢板的动态响应与破坏机理

A pre-holed Q235 steel plate subjected to foam projectile impact is numerically investigated to assess the structural damage caused by combined blast and fragment loading upon detonation of cased explosives. The validity of the numerical model is checked against experimental measurements. The validated model is then employed to investigate the dynamic response, deformation / failure modes and hole-edge deflection of the pre-holed plate. The physical mechanisms of tearing failure initiated around the pre-hole are revealed using the stress triaxiality and Lode parameter for describing the state of stress. The influences of hole diameter and plate thickness on the impact resistance and failure mechanism are also quantified. Results show that the presence of a pre-formed hole significantly curtails the impact resistance of the steel plate: With increase in hole diameter or decrease in plate thickness, the hole-edge deflection of the steel plate grows, while the projectile momentum causing tearing failure drops.