Granular composite formulations involving metal/metal [1,2] (intermetallic) reactions have been investigated for a number of applications. Interfaces between metallic particles have been attributed particular importance due to their ability to form localized hotspots, where the local temperature of the granular composite may significantly exceed the global temperature, leading to a localized reaction initiation that may initiate a global reaction.3 Understanding of the response of metal/metal granular composites to mechanical loading can be greatly facilitated by mesoscale modeling in which the underlying composite structure of the components is clearly resolved. For the Al/Ni composite discussed in this study, this involves explicitly resolving Al and Ni particles and intermetallic (Al/Al, Ni/Ni and Al/Ni) interfaces. In this work we utilize an idealized but realistic model for an Al/Ni composite using EOS, constitutive and interfacial models informed by molecular dynamics (MD) simulations. The Al/Ni microstructures are subjected to uniaxial compressive loading up to 30 GPa, shock loading up to 70 GPa (2000 m/s) and impact loading at 2000 m/s, and the mechanical and thermal response of the composite are analyzed.