The shock and release behavior of both alumina-filled and unfilled epoxies are examined in planar impact experiments. The various materials investigated can be used as encapsulants in applications such as shock-activated pulsed power supplies. Characterizing their dynamic behavior under shock loading and subsequent release is part of a larger effort to develop predictive numerical models for the performance of these power sources. In the current study, reverse-impact techniques were used to establish Hugoniot states and subsequent release profiles for each material at several impact conditions. Laser interferometry (VISAR) was used in these experiments to determine the particle velocity history at the impact interface formed by a projectile-mounted epoxy sample and a stationary fused silica target. Conventional impact configurations and VISAR were used to observe transmitted waveforms under corresponding shock loading conditions. Transmitted waveforms at multiple Lagrangian locations were also recorded in selected experiments using embedded PVDF piezoelectric films. The results show expected differences in the dynamic properties of filled and unfilled epoxies, and similarities in the properties between different filled or unfilled epoxies. Comparisons between VISAR experiments and PVDF gauge experiments may indicate a rate-dependent response in this gauge material.

A damage initiated reaction (DMGIR) computational model is being developed for the CTH shock physics code to predict the response of an explosive to non‐shock mechanical insults. The distinguishing feature of this model is the introduction of a damage variable, which relates the evolution of damage to the initiation of reaction in the explosive, and its growth to detonation. The DMGIR model is a complement to the History Variable Reactive Burn (HVRB) model embedded in the current CTH code. Specifically designed experiments are supporting the development, implementation, and validation of the DMGIR numerical approach. PBXN‐5 was the initial explosive material used experimentally to develop the DMGIR model. This explosive represents a family of plastically bonded explosives with good mechanical strength and rigid body properties. The model has been extended to cast explosives represented by Composition B.