Influence of pre-existing interfacial damage on the ballistic behavior of ceramic composite armor systems: An experimental and numerical analysis

In recent years, Ceramic Composite Armor Systems (CCAS) have gained extensive applications in protective configurations of various armored weapon platforms due to their exceptional ballistic behavior. Nevertheless, the integration of functional modules into cohesive interfaces for enhancing CCAS intelligence presents a technical paradox: such modifications inevitably induce pre-existing interfacial debonding/delamination defects that may adversely affect ballistic behavior. Using a simplified Al₂O₃/Carbon Fiber (CF)/Aramid Fiber (AF) composite armor configuration as a representative example, this work systematically examines through combined Ballistic Limit Test (BLT) and Finite Element Analysis (FEA) how pre-existing damage parameters (including location, area and quantity) at both Al₂O₃-CF and CF-AF interfaces influence critical ballistic behavior responses, especially the residual velocity, back face deformation, damage circumstance and its extension patterns, etc. The results of the FEA are validated with the experimental results. The key findings reveal that under equivalent damage areas with single pre-existing damage, interfacial debonding at the Al₂O₃-CF interface demonstrates more pronounced ballistic behavior degradation compared to the CF-AF interface defects. This detrimental effect exhibits amplification beyond critical damage tolerance thresholds. Under dual pre-existing damage conditions, the detrimental effects on the ballistic behavior of the CCAS exhibit significant dependence on damage area combination characteristics.