Quasi-static and dynamic response of energetic materials

As explosives are subjected to increasingly extreme conditions, there has been more desire to develop models to predict their performance, sensitivity, and mechanical response. In order to develop these models, however, experimental data are needed for validation. To this end, a series of quasi-static and dynamic mechanical tests have been performed on two similar energetic materials. This has allowed the mechanical response to be characterized for strain-rates ranging from 10(exp -4)/s - 10(exp 3)/s by incorporating both quasi-static load frames and a Split-Hopkinson Pressure Bar (SHPB). Additional tests have been performed using the SHPB in order to characterize the mechanical response of the explosives under confined conditions. Still additional experiments using the dynamic mechanical analyzer (DMA) have been performed in order to determine the effect of strain-rate on the glass transition temperature of the explosives. The experiments show that the yield stress and modulus of the energetic materials rise approximately 10% as the strain-rate is increased from 10(exp -4)/s - 10(exp -2)/s. However, as the strain-rate is increased to 10(exp 3)/s, the yield stress of the energetic materials increases more dramatically. This behavior is most likely due to a transition from the rubbery regime to a leathery response in the polymer binder and is consistent with earlier experiments conducted on polymer binders indicating an increase in strain-rate sensitivity between 10(exp 2)/s and 10(exp 4)/s.