Mechanical behavior of a typical polymer bonded explosive under compressive loads

The compressive mechanical behavior and damage mode of polymer bonded explosives (PBXs) based on hexahydro-1, 3, 5-trinitro-1, 3, 5-s-triazine (RDX) were systematically investigated via experiments and simulations. The strength sensitivity on strain rate of PBX–JH14C was studied using quasi-static and dynamic uniaxial compressive tests. The axial and radial stress history curves were measured using a passive confining experiment, and characterizations of the behavior of PBX–JH14C were studied under dynamic multi-axial loads. The results showed that the dynamic stress-strain curves of PBX–JH14C exhibited an evident strain rate effect. Combining theoretical and meso analyses, the damage characteristics of PBX–JH14C under low speed impacts were studied. A constitutive theory was developed for modeling the dynamic mechanical response of PBX–JH14C by using the Boltzmann superposition principle with a Prony series representation. Mathematical presentation of the relaxation modulus can be obtained by fitting the modulus master curve. The model was verified by comparing the finite element simulations with experimental results. Furthermore, it was observed that the theoretical prediction coincided with experimental results. The damage mode and mechanisms of PBX–JH14C were discussed based on the experimental and theoretical studies. In the absence of confinement, interface debonding and matrix cavitation were the predominant failure mechanisms under low speed impact.