Effect of Particle Mass Fraction on the Multiscale Dynamic Failure Behavior of Particulate Polymer Composites

In this study, the effect of particle mass fraction on the dynamic multiscale behavior of particulate polymer composite is investigated. High spatiotemporal resolution digital image correlation-based experiments are conducted to understand the local deformation and the failure mechanisms. The deformation fields at different length scales are compared to each other to understand the link between macroscaleand mesoscale behavior. All the experiments are carried out on polymer bonded sugar, a well-known mechanical simulant of polymer bonded explosives, with varying particle mass fraction. The transition of the soft binder dominated stress-strain behavior to a quasi-brittle type behavior was observed as the particle mass fraction is increased. The mesoscale experiments show that in samples with lower mass fraction, the deformation is mainly controlled by the binder. Whereas, at a higher mass fraction, the crystals are engaged in the load transferring process through the formation of force chain in the material. The formation of the force chain causes stress concentration followed by a brittle failure mode.