The present paper describes work on the thermal behaviour of selected energetic materials ranging from single explosive compounds to explosive mixtures using standard DSC and TGA equipment as a preliminary evaluation prior to cook-off testing in a specifically designed test vehicle. The behaviour of the pure explosives was as expected since evaporation of the solid/liquid produced low values for the thermal output from the decomposition. This was confirmed by the absence of the exotherm for the TNT decomposition for mixtures containing ≥ 60% RDX. This could also be consistent with the products of the RDX decomposition reacting with the TNT below the normal TNT decomposition temperatures. However, thermograms from the mixtures were simple additions of those from the individual components. Also described are preliminary trials of a demountable instrumented test vehicle designed for cook-off experiments. The equipment sensors will provide data on temperature profiles as well as cook-off temperature. Tests have been performed on the vehicle in order to evaluate the mechanical behaviour of the structure under cook-off conditions. Temperature measurements indicated efficient heat transfer through the vehicle walls and the rapid temperature stabilisation inside the vehicle chamber. Further tests on the pressure transducers and stress/strain gauges, intended to assess the distortions suffered by the testing vehicle as the reaction develops, are in progress. The designed testing vehicle should produce suitable experimental data for computer modelling of explosives decomposition during simulated cook-off tests to evaluate reaction mechanisms.
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