Development of a Model for Rock Damage Caused by Plastic Strain and Its Application

The microcosmic mechanism of rock's plastic deformation and damage variables is microcosmic crack's bud and development of rock.Therefore plastic deformation and damage come forth at the same time and their evolving rule is coupled each other.Rock's plastic strain serves as damage variable and direct-ratio relation of rock's plastic strain and damage is defined.Rock's critical damage and critical strain are related by normalization method.Then rock's plastic strain damage model and constitutive model are set up.By comparing the stress-strain curve obtained from the test with the theoretical stress-strain curve attained from a plastic stain damage model,a conclusion comes out clear that the theory is consistent with tested datum.It is shown that the rock's plastic strain damage model is suitable for the description and analysis of the relationship between the damage and stress or strain during loading process.By using rock's plastic strain damage model and tested datum,the relation between rock's damage and stress,damage and strain can be analyzed.