The Influence of Formulation Variation and Thermal Boundary Conditions on the Near-Resonant Thermomechanics of Mock Explosives

Abstract

The thermomechanics of energetic and inert particulate composite materials are of pronounced interest in the defense community. This work seeks to further characterize the macroscale, thermal and mechanical response of these materials under various near-resonant mechanical excitations. The fabrication of mock energetic samples based on the PBXN-109 formulation, comprised of hydroxyl-terminated polybutadiene (HTPB) binder with 85% solids loading and varying additive content (0%, 15%, and 30%) of sucrose and/or spherical aluminum crystals, enabled a systematic investigation into the effect of formulation variation on the thermal and mechanical response. Experiments were also performed on insulated plate samples of identical composition to examine the effect of varying thermal boundary conditions. In each of these experiments, the samples were mechanically excited using an electrodynamic shaker, while their thermal and mechanical responses were recorded using an infrared camera and scanning laser Doppler vibrometer, respectively. The investigation of these responses aids in the effort to characterize and understand the behavior of polymer-bonded explosives under mechanical excitation.