Innovative Method to Correlate Sub-Scale to Full-Scale Insensitive Munition Tests

This project has two objectives: bridge the gap between subscale and full-scale insensitive munitions (IM) experiments, and identify an “optimal” set of IM subscale tests. Size, shape, and boundary conditions are critical to the outcome of IM tests. Consequently, subscale experiments are insufficient to determine IM properties of munitions. Full-scale experiments are expensive, and can be performed only late in the development cycle. Thus, developers cannot depend on full-scale tests for design optimization, while subscale tests are insufficient. Consequently, conservative designs are adopted. A physics-based coupled thermal-mechanical-chemical model is proposed to resolve this setback. This model can represent complex geometries, boundary conditions, and mix of materials (e.g., energetic component, and inert structural materials such as liner and casing). The scale gap is bridged in two steps. First, the model is applied to simulate subscale tests. Then, having succeeded in the first step, simulate full-scale experiments. The obtained predictions will be deemed reliable because of the generality of the approach, and the success in simulating subscale tests. Having the model will also permit the undertaking of sensitivity analyses of subscale tests. These studies will enable modifying, or replacing, tests so as to better span the performance envelop experienced by full-scale munitions.