The Influence of the Contact Boundary in a Metal Matrix Composite on Dynamic Loading

Direct numerical modeling of heterogeneous materials enables calculation, determination of elastic characteristics, and assessment of the fracture of reinforced heterogeneous materials. However, the question of which boundary conditions to set at the interface between the macro-inclusion and the matrix remains open. Using the technology of direct numerical construction of a heterogeneous environment, numerical modeling of the loading of metal matrix composites by a flat shock wave was conducted, formed by an impacting heterogeneous plate. A comparison of boundary condition types with an additive mixture model was performed. It is demonstrated that the direct numerical modeling of a heterogeneous material without fracture under shock wave loading aligns with the additive law of mixtures. The study reveals that, for macro-inclusions under dynamic loading, the type of boundary conditions has minimal influence on the final result in the case of elastoplastic loading by a flat shock wave, disregarding fracture. The impact of the type (model) of the contact boundary on a barrier of finite thickness is considered. For a more detailed investigation of the influence of boundary conditions on material interfaces during destruction, a model problem of a steel rod penetration with a spherical head into a Metal Matrix Composite (MMC) barrier of finite thickness was examined. It is demonstrated that, during extensive material deformations leading to fracture and the formation of new surfaces, the type of boundary conditions significantly influences the final outcome by determining the fracture mechanism.