The growth and evolution of elliptical micro-cracks in quasi-brittle materials

Growth and evolution of micro-cracks are the mechanism of damage and failure for quasi-brittle materials. The principle for growth and evolution of micro-cracks in quasic-brittle material subjected to loading is studied. The analytical solution is given for the growth of elliptical micro-cracks in elastic deformation stage by the method of complex potential functions. The critical stress condition for the starting damage is derived based on micro-crack growth criterion. The constitutive relation is developed based on the conservation of energy during the wing-crack propagating.