Characterization and evaluation of silicon carbide for high-velocity impact

This article presents a characterization and evaluation of silicon carbide for high-velocity impact. This includes a wide range of loading conditions that produce large strains, high strain rates, and high pressures. Experimental data from the literature are used to determine constants for the Johnson-Holmquist-Beissel (JHB) constitutive model for brittle materials. A previous article by the authors presented a characterization of silicon carbide for high-velocity impact using an earlier version of the model (JH-1). The previous work provided good agreement with a broad range of experimental data with the exception of high-velocity penetration data. The current work uses the more recently developed JHB constitutive model, a target geometry that more closely matches the experimental design, and a computational technique that allows for target prestress. These recent developments (primarily the prestress) produce computed results that agree with all the experimental data, including the high-velocity penetration data. The computed results also provide a detailed analysis of the penetration process into a prestressed target and show why it is necessary to include the target prestress. A specific result is the ability to reproduce the nonsteady penetration rate that occurs in the prestressed target. (C) 2005 American Institute of Physics.