Investigation Of Mechanisms Of Ceramic Composite Target Under Noncentral Impact Of Armour-piercing Projectile

The process and mechanism of ceramic/mild steel composite target impacted by 7.62mm armour-piercing projectile (APP) were investigated by experiment, numerical simulation and analytical model.Great emphasis is laid on the noncentral impact ballistic performance and mechanism of the composite target. The main contents and innovative work include:(1)Ballistic experiments of composite target against APP were designed and carried out,and the damage characteristics of each part of the composite target were analyzed. Limit velocity, the radius of cone and its smash region were obtained. The results show that the main mechanism of ceramic composite target against 7.62mm APP is the transform function from penetration of projectile into impact due to the projectile smashing and ceramic cone forming. The ballistic performance of composite target is influenced by the impact point. The in which the influence of impact point could be ignored. 5mm edge area is discarded from the effective protective area.(2)The penetration process of ceramic/metal target in centre area of the target under APP involves three stages through the numerical analysis: the first stage, the projectile is seriously smash and velocity decrease sharply, the ceramic cone form and obtain the same velocity with the projectile; the second stage, the residual projectile and the cone impact backing plate. The velocity decrease of the projectile is inconspicuous and the erosion stop; the third stage, the residual projectile impact backing plate and the velocity decrease sequentially.(3)Based on the results from the experiments and numerical analysis, an analytical model for limit velocity was established. The results from the present model are in good agreement with experiments previously published and ours. The energy dissipation mechanism was discussed. It is shown that the main mechanism of energy dissipation is the energy dissipation of the backing plate and the projectile due to its smashing, about 60% to 95% and 5% to 40% of the initial kinetic energy respectively. The energy dissipation of the adhesive layer is less than 5%.(4)Ballistic performance of the composite target under the noncentral impact condition is studied by numerical simulation. The main mechanism of composite target is the energy dissipation of front plate and projectile rotation during penetrating the backing plate. The energy dissipation of front plate and the projectile rotation is prominent when the impact point is apart from the target edge about 1/4 length of the target.(5)The optimal cell length of the composite target is analyzed by a published destroy probability model. When the probability of the first round impact is defeated exceeds 0.7,the cell length has to be more than 70mm; When the probability of the third round impact is defeated exceeds 0.5,The cell length need to be not less than 120mm;...