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Ballistic performance of ultra-thin graphene membranes have recently been investigated at the micro and nanoscale. Two open questions that remain unanswered are, how graphitic plates behave when they can no longer be treated as a thin membrane, and how the projectile shape influences the perforation resistance of plates of varying thicknesses. Through coarse-grained molecular dynamics simulations, we show that beyond a critical plate thickness, a cylindrical projectile penetrates the plate at a lower velocity than a spherical one. This counterintuitive phenomenon is explained by spalling-like failure for thicker plates, where the graphene layers at the bottom section undergo a wave-superposition induced failure in the cylindrical case. Finite element simulations are carried out to show that in-plane tensile stress concentrates at the bottom section, resulting from the superposition of incident and reflected stress …