Chapter 24. A Physically-Based Model for the Effect of Microstructure and Mechanical Properties on Ballistic Performance

Summary

Recovery of ceramics from ballistic experiments in which impacting ductile long-rod projectiles failed to penetrate has led to the observation and understanding of the localized damage mechanisms beneath the region of impact. The shape of the damaged region indicates that these mechanisms are shear-assisted. Based upon these observations, a model for the transition between no penetration and penetration was formulated by combining a micromechanics -based compressive failure model with Hertz's theory for frictionless contact between axisymmetric linear-elastic bodies. The resulting model indicates the relative significance of a ceramic's grain size, short-crack fracture toughness, yield strength, Poisson's ratio, coefficient of friction, and critical crack-length on the dwell/penetration transition. A brief review of the derivation and predictions of the model are presented.