| Abstract |
In an effort, to understand the mechanism causing sympathetic detonation, a concurrent calculational/experimental research program was initiated. The primary objective of this work was to predict the propensity of a given energetic formulation to sympathetically detonate in the storage configuration, Results from initial testing suggested the primary energy transfer mechanism associated with sympathetic detonation events involve flyer plate-like impact To accurately describe the initial shock environment at the acceptor, accounting for pressure reduction due to divergence and donor plate thickness at impact, a simplified model was developed. It incorporated the JWL description of the donor energetic material isentrope, the unreacted Hugoniot of the acceptor energetic material, and a model derived from hydrocode analysis of the event. Donor casewall expansion velocity, peak pressure, and pulse thickness generated at casewall (flyer-plate) impact with an acceptor and divergence, and rarefaction losses were calculated. Pressure data from the impact are compared to pop plot data for the acceptor energetic material as an indicator of the materials ability to survive these conditions. In conjunction with the calculational effort, a flyer plate test was developed to simulate the boundary conditions found in representative donor and acceptor test configurations. Large flyer plates, 175 mm diameter by 5 to 9 mm thick, were explosively launched at velocities between 1.2 and 2.1 km/sec, which closely match the calculated casewall velocities from donor charges of interest to munitions storage problems. Runups to detonation were measured and margins of safety were determined. The insensitive materials used in these experiments were AFX-I 100, a desensitized Tritonal and variations of AFX-. |
