Abstract:
To overcome the limitations of classical continuum mechanics in modeling brittle fracture under impact loading, a bond-based peridynamic framework was adopted to accurately predict crack propagation in transparent ceramics. A numerical model simulating tungsten carbide fragments’ impacts on YAG transparent ceramic was developed and validated through edge-on impact experiments. The model elucidated the dynamic crack-evolution mechanisms during penetration, and quantitatively assessed the roles of impact velocity, energy-release rate, and fragment shape in governing crack propagation. Results reveal a three-stage failure sequence: (i) comminuted-zone expansion, (ii) crack propagation, and (iii) fragment ejection. As impact velocity rose, the damage rate increased and then plateaued; the propagation angle of primary cracks remained essentially constant at higher velocities. Secondary-crack clusters migrated toward the impact axis with increasing velocity and vanished at sufficiently high speeds. Raising the ceramic’s energy-release rate markedly suppressed comminuted-zone formation yet exerted a negligible influence on the final fracture pattern. Compared with conical projectile, spherical and cylindrical projectiles produced distinctly different crack networks while inflicting less overall damage. Once the ceramic layer exceeded a critical thickness, the PVB interlayer in YAG/PVB/glass composite targets effectively arrested crack propagation. The findings provide a robust tool for quantitatively analyzing crack propagation, accurately predicting impact damage, laying the groundwork for lightweight, high-strength, and optically integrated transparent composite structures.