摘要
The stress shielding effect of profuse microcracks at the tip of a macroscopic stationary mode Ⅰ crack is studied. The analysis method adopted combines the micromechanical approach with the effective elastic medium approach. The anisotropic constitutive relation of the effective elastic medium is based on the DMG damage model developed by the authors for microcrack weakened brittle materials undergoing damage in form of elastic modulus degradation as a result of stable microcrack growth. The stress and strain fields at the crack tip and the condition of path independence of J integral in the damage zone are discussed under some reasonable approximations. A modified J integral method is thereby proposed to calculate the ratio of near tip to remote stress intensity factors and compared with the conventional method of J conservation.
The stress shielding effect of profuse microcracks at the tip of a macroscopic stationary mode Ⅰ crack is studied. The analysis method adopted combines the micromechanical approach with the effective elastic medium approach. The anisotropic constitutive relation of the effective elastic medium is based on the DMG damage model developed by the authors for microcrack weakened brittle materials undergoing damage in form of elastic modulus degradation as a result of stable microcrack growth. The stress and strain fields at the crack tip and the condition of path independence of J integral in the damage zone are discussed under some reasonable approximations. A modified J integral method is thereby proposed to calculate the ratio of near tip to remote stress intensity factors and compared with the conventional method of J conservation.
