Investigation Of Mechanism And Performance Of Spaced Ceramic Target Under Impact Of 12.7mm Armor Piercing Projectile

Based on ballistic experiments, the process and mechanism of spaced ceramic target (SCT) impacted by 12.7mm armor piercing projectile (APP) were investigated by numerical simulation. Great emphasis is laid on the thickness matching and the effects of space and impact point. The main contents and innovative work include:(1) The residual penetrating capacity of the projectile after penetrating the ceramic or ceramic/steel plate was put forward and investigated. The results show that the residual penetrating capacity can be denoted by the residual kinetic energy of the largest debris and the numerical results are in great agreement with experiments. The impact velocity and thickness of ceramic plate are important factors which affect the residual penetrating capacity of projectile.(2) The experiments of spaced ceramic/steel target (SCST) against 12.7mm APP were carried out and the penetration process and mechanism were investigated with 3D commercial code ANSYS/LS-DYNA. The results show that the penetration process involves four stages: the stage of penetrating front plate, impacting backing plate, traversing space and impacting mother plate. The main mechanism of the target is dissipating energy under central impact and the energy dissipation of the projectile is mainly during the stage of impacting backing plate. When the impact point is not in edge area, there are both dissipating energy and yawning mechanism, so the ballistic performance of target is improved due to the yawning mechanism of the ceramic/steel plate. When the impact point is in edge area, the yawning mechanism is conspicuous but the dissipating energy mechanism is too little, so the ballistic performance of target is poorer than the central impact.(3) The effect and mechanism of space of SCT was investigated. The results show that the space is disadvantageous to the ballistic performance of the target and the effect is related to the breadth of the space. The mechanism is that, with the increasing of the space breadth, the support of mother plate to backing plate and confine of backing plate to the conoid decrease, but the energy dissipation of backing plate increase. As far as the SCST is concerned, the most disadvantageous breadth of space is 7.5mm and the most advantageous one is 15mm. When the breath is larger than 30mm, it has hardly any relation to the space effect.(4) The thickness matching of SCST against 12.7mm APP was investigated. The better thickness ratio hc/hb of the ceramic/steel plate is between 5 and 9 when impact velocity is exceed the ballistic limit, and the effect of boundary can be neglected. For a SCST whose area density is 123.6g/cm~2, the thicker the mother plate is, the poorer its ballistic performance is when the thickness ratio hc/hb is constantly in the better range.