A CONTINUUM DAMAGE MODEL FOR FRACTURE OF BRITTLE SOLIDS UNDER DYNAMIC LOADING

A continuum damage mechanics description of elastic-brittle fracture provides an appropriate constitutive model for impact simulations involving ceramic, rock, or similar materials. For an orthotropically damaged solid, a complementary energy function may be derived from a mesomechanical description of three orthogonal arrays of coalescing cracks. Damage evolution equations suggested by dynamic fracture test measurements may be expressed in terms of tensor power functions which generalize classical one-dimensional analyses. Measured Weibull strength distributions may be employed to account for flaw size distribution effects on the damage accumulation rate. The resulting model avoids the introduction of effective stress assumptions or the use of specialized material property coefficients obtained from nonstandard mechanical tests.