This report describes the implementation of a fully three-dimensional rate, pressure, and damage-dependent constitutive model for brittle materials such as ceramics into the explicit, Lagrangian finite element code DYNA3D. The model, otherwise known as the Johnson-Holmquist II QH-2) ceramic model, has also been implemented into CTH, EPIC, and LS-DYNA, and is used extensively in modelling the brittle response of ceramics in armor applications. The DYNA3D material driver was used to verify the model implementation for constant strainrate input histories Qohnson, G. R., and T. J. Holmquist. "An Improved Computational Constitutive Model for Brittle Materials." High Pressure Science and Technology, New York:AIP Press, 1993). Also described is the implementation of the JH-3 ceramic model and capabilities for modelling projectile dwell phenomena. The Johnson-Holmquist series of ceramic models (JH-1, JH-2, and JH-3) is currently being used in a broader program aimed at computational optimization of composite lightweight armor for Future Combat System vehicles.n