Validation of Hypervelocity Impact Iduced Damage and Fragmentation Models for Silicon Carbide

Abstract The performance envelope associated with hypersonic flight and atmospheric reentry demands materials used in thermal protection systems that can sustain structural integrity at temperatures over 1,000°C. Given these rigorous conditions, material options are confined to ultra-high temperature ceramics (UHTC) and ceramic matrix composites (CMC) incorporating UHTCs, chosen for their exceptional resistance to extreme temperatures and favorable strength-to-weight ratio. Silicon carbide (SiC) emerges as a useful model material for these applications, replicating crucial material attributes such as thermal fatigue and shock resistance. Beyond SiC’s thermal properties, its Hugoniot Elastic Limit (HEL) closely aligns with that of UHTCs utilized in the aerospace and defense sector. While assets are in flight at hypervelocity, any debris within the flight path can become a projectile causing hypervelocity impact. When impacted, compressive shock waves propagate radially causing rarefactions when interacting with the free surface boundaries of the material. These rarefactions can amplify and cause a tensile state leading to fracture of the material. Understanding these tensile amplifications is crucial to understanding material performance from a fracture mechanics viewpoint rather than the classic determination of spall strength and cratering. This study aims to illuminate these propagating fracture patterns shown in-plane of the impacted surface.