A simulated and experimental investigation into the effect of casing material fracture on the axial explosive performance of cylindrical charges

Current models to predict the damage response of solids are based on empirical data from indirectly applied shocks or gradual strain increases. Neither of these conditions accurately represent the conditions a solid charge casing undergoes during explosive detonation: extremely high pressures, with zero buildup, over a short duration. The response to such conditions have been validated in air, as the shock wave can be easily observed experimentally. Validation for solids, with low visibility in the immediate contact region and an inability of most sensors to operate under the harsh conditions produced by detonation, results in the need to observe, not the response of a solid casing, but the secondary response of a witness material. This report presents information from the Plate Dent Test as a way of identifying measurable differences in the behavior of charge casings. One inch diameter Composition-B charges are cased in polyurethane, acrylic, or metal and detonated on top of a metal witness plate. The dent produced by the explosive on the witness plate is compared to three predictive simulations to validate the test's ability to distinguish between casing materials and to identify the most accurate simulation technique.