Computational investigation of structured shocks in Al/SiC-particulate metal-matrix composites

摘要

Purpose - Propagation of planar (i.e. one directional), longitudinal (i.e. uniaxial strain), steady (i.e. time-invariant) structured shock waves within metal matrix composites (MMCs) is studied computationally. Waves of this type are typically generated during blast-wave loading or ballistic impact and play a major role in the way blast/ballistic impact loads are introduced in, and applied to, a target structure. Hence, the knowledge of the basic physics of propagation of these waves is critical for designing structures with superior blast and impact protection capabilities. The purpose of this paper is to help advance the use of computational engineering analyses and simulations in the areas of design and application of the MMC protective structures. Design/methodology/approach - To derive the overall response of the composite material to shock type loading, a dynamic-mixture model is employed. Within this model, the known constitutive responses of the constituent materials are combined using the appropriate mixture rules. These mixture rules are of a dynamic character since they depend on the current state of the composite material-and cannot be applied prior to the beginning of the analysis. Findings - The approach is applied to a prototypical MMC consisting of an aluminum matrix and SiC particulates. Both the intermediate-to-strong shock regime (in which the contribution of stress deviators to the stress field can be ignored) and the weak shock regime (in which stress deviators provide a significant contribution to the stress field) are investigated. Finally, the computational results are compared with their experimental counterparts available in the open literature in order to validate the computational procedure employed. Originality/value - Prediction of the spallation-type failure in a metal-matrix composite material (modeled using the dynamic-mixture model) has not been done previously.