Research objective: We study the action of shock waves on composite materials with inclusions, as in solid-fuel rocket grains. The need to resolve shock fronts and interfacial damage processes between the matrix and the inclusions makes this a multiscale simulation problem. Numerical simulations predict mechanical response, including shock–induced dewetting of inclusions. Approach: Adaptive spacetime discontinuous Galerkin methods solve multiscale elastodynamics problems; a nonlinear cohesive traction–separation law models the dewetting process. Significant results: In a first high-resolution study of this problem, we observe a complex history of dewetting and rewetting driven by reflections and focusing of shocks between and within the inclusions. Broader impact: These studies provide new insights into the complex behaviour of composite materials under shock loading. These provide a foundation for understanding microstructural damage mechanisms in composite systems and a necessary foundation for modelling detonation in energetic materials. Research Assistants: Reza Abedi, Morgan Hawker; Dept. of Theoretical & Applied Mechanics Research Scientist: Karel Matous, Center for Simulation of Advanced Rockets Elastodynamic simulation of particle dewetting: An adaptive spacetime discontinuous Galerkin model simulates shock– induced dewetting and rewetting of stiff inclusions. Height and color fields depict velocity magnitude and strain-energy density. Reflections, surface waves and focusing effects within the circular inclusions create a complex history of dewetting and rewetting.