Computational Analysis of Multi-body Projectile Structures during Hypervelocity Impact

Hypervelocity impact and resulting penetration and cratering phenomena have long been of interest to both defense and scientific communities. At its core, the ability to predictively model such events requires a comprehensive understanding of all interacting materials including EOS/constitutive response, body geometries, and initial impact conditions including velocities and orientation. While there is a wealth of historical literature exploring such dynamic events, most emphasize simplified projectile geometries with minimal or no sub-structure. Recent applications have driven new interest in complex multi-body projectiles and any potentially unique impact behaviors. Using the CTH shock physics hydrocodes, the work presented herein examines a single dynamic event consisting of a steel projectile impacting a well characterized soil target. While keeping impact conditions constant, the internal structure of the projectile is varied in complexity with the inclusion of cavities and sub-structure. Variations in projectile design were such that mass was held near constant thus maintaining kinetic energy of the impact problem. Results review observed penetration/cratering behaviors, correlating to variations in plastic deformation for each case. Potential implications for broad (engineering-scale) empirical expressions are discussed, and limited experimental benchmarking is provided based on available historical data. SAND2023-04961A