A Pressure-Dependent Damage Model for Energetic Materials
ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
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Sub-detonative events occur when the explosive material in an energetic system reacts without fully detonating for example, mechanical insult of an energetic system can result in either an explosion or deflagration, with much of the explosive either unreacted or burning. Despite this lack of detonation, the energetic response can still be quite violent and present safety issues to nearby systems and personnel. The investigation of sub-detonative response requires the consideration of an energetic material s mechanical strength because the plastic deformation and subsequent cracking of the energetic material influences both the reaction evolution e.g., accelerated burn rate with increased surface area and the level of violence in the response. In this report, the kinematic homogenization approach of Hill and Mandel, a method that has been traditionally used in deriving yield criteria for void-metal aggregates, will be utilized in deriving a yield criterion for describing the mechanical response of energetic materials. The derived yield criterion is able to capture the strength-differential under constant pressure, which is expected in an energetic material, along with its dependence on both pressure and accumulated damage. The eventual goal is to be able to couple, in a consistent and physically meaningful manner, the energetic material s mechanical response through the yield criterion, appropriate damage nucleation and evolution laws, and the equation of state with its reactive response.
- Ammunition and Explosives