Mechanisms of fragmentation of aluminum-tungsten granular composites under dynamic loading

Numerical simulations of aluminum (Al) and tungsten (W) granular composite rings under various dynamic loading conditions due to explosive loading were performed. Three competing mechanisms of fragmentation were observed: a continuum level mechanism generating macrocracks with a size scale comparable to the case width, a mesoscale mechanism generating voids and microcracks at the unbonded Al/W interfaces due to tensile strains, and mesoscale jetting due to the development of large velocity gradients between the W particles and surrounding Al. These mesoscale mechanisms can be used to tailor the size of the fragments (macro to mesoscale) by selecting an appropriate initial mesostructure for a given loading condition.