SBIR-STTR Award

The objectives of phase I are to determine how well the small scale tests currently used for screening explosives, and the models that describe explosive behavior in the small scale test and in the full scale munition, can predict thresholds of explosive reaction in the operational full scale munition. Full scale munitions will be studied to determine the critical mode(s) of explosive reaction that will dictate which kinds of small scale tests will produce the pertinent explosive sensitivity data. Discrete element models of the small scale tests and the operational munition will be applied in order to define the explosive reaction threshold common to both situations. Areas of predictive deficiency will be identified for a phase II improvement program.

The overall problem is to develop the technology of small scale testing to the point that the properties of new explosive formulations may be measured and used to predict full scale munition performance. In Phase I it was found that this approach appears feasible in terms of two measurable explosive properties, a pressure sensitivity threshold (P (c)) and an energy sensitivity threshold (E (c) = p (2) t / c (10) U) which must both be exceeded for energetic reactions to occur. Further, it was found that enough small scale tests exist, or can be developed without too much difficulty, to measure these properties of explosives. Similar basic properties of explosives that should be employed in computer models to account for shear and friction energy inputs are not easily measurable at present. Phase II is designed to improve specific small scale E-P tests with the objective of configuring an E-P facility that can efficiently evaluate explosive sensitivity, and to develop comparable technology of small scale testing for the effects of shear and friction.