Criterion for interface defeat to penetration transition of long rod projectile impact on ceramic armor

In this paper, an analytical model for the prediction of damage evolution, through impact of long rod projectile (LRP), at interface defeat condition, against silicon carbide (SiC) target is developed. The model comprises four calculation parts, namely interface pressure distribution, stress state in the ceramic target, wing cracks micro-mechanical and macro-cone crack propagation. A micro-mechanical constitutive model with wing crack distribution is used for inelastic deformation of ceramic. Subsurface damage evolution in ceramic impacted by blunt and conical LRPs at different impact velocities and length scales are presented to depict the potential mechanisms involved in transition from interface defeat to penetration. The damage evolution results agree well with the available literature experimental measurements. The proposed possible criteria can be used to predict the interface defeat to penetration transition for blunt and conical LRPs.