DYNAMIC DAMAGE EVOLUTION IN BRITTLE SOLIDS

For brittle solids containing preexisting microflaws, a two-dimensional model is developed to simulate dynamic damage evolution in uniaxial compression. Frictional, and rate-dependent and rate-independent plastic constitutive relations are considered to describe the deformation of preexisting microflaws. The inelastic deformation of microflaws is assumed to produce tensile microcracks in the matrix. These microcracks emanate from microflaws and grow in the direction of compression. Numerical calculations employing the dynamic damage evolution model are carried out to illustrate the resulting overall response of the solid. The propagation of a compressive stress pulse in a semi-infinite bar is studied to demonstrate the stress-pulse attenuation due to compression-induced microcracking, and frictional deformation and inelastic flow of preexisting flaws, including the rate effects.