Application of Damage Evolution Equation Under Coupled Compression-Shear to Constitutive Model of Concrete

Combined the concept of equivalent micro voids system with the model of existent damage-nucleation growing up, a damage evolution equation of brittle materials under the coupled compression-shear actions is presented by strict mathematical derivation based on some physical theorems. The parameters in damage evolution equation could be gotten by applying the damage evolution equation to the brittle-elastic damage constitutive model of concrete and simulating result of experimental stress-strain curve. From the damage constitutive relation and the damage evolution equation, the damage-time curve can also be obtained, which is consistent quite well with the pictures of internal micro voids evolution gotten from CT technology. The presented damage evolution equation reveals the macro-microscopic development mechanism of the coupled compression-shear damage in brittle materials. This work establishes a good basis for the computation and analysis of high velocity penetration problems.