Crack propagation in an orthotropic medium

Crack propagation in an orthotropic medium under general loading

Transient elastodynamic antiplane crack analysis of anisotropic solids

The generalized plane problem of a finite Griffith crack moving with constant velocity in an anisotropic piezoelectric material is investigated. The combined mechanical and electrical loads are applied at infinity. Based on the extended Stroh formalism, the closed-form expressions for the electroelastic fields are obtained in a concise way. Numerical results for PZT-4 piezoelectric ceramic are given graphically. The effects on the hoop stress of the velocity of the crack and the electrical to mechanical load ratios are analyzed. The propagation orientation of a moving crack is also predicted in terms of the criterion of the maximum tensile stress. When the crack speed vanishes, the results of the present paper are in good agreement with those given previously in the literature.

On a moving Griffith crack in anisotropic piezoelectric solids

Extending the polarization saturation (PS) model and Yoffe crack model for ferroelectric materials, a moving PS model is proposed to study the problems of crack propagation considering the electrical nonlinearity. The model is solved using continuous distribution dislocation method. And the explicit expressions of the size of the electric saturation zone, intensity factors and the local energy release rate for the moving PS model are derived. It can be deducted from this model that the intensity factors and the size of the electric saturation zone are independent of the velocity of the crack. The local energy release rate for the moving PS model has the form of that for a stationary crack multiplied by the local energy release rate universal function f(v). And it increases monotonically with increasing v. When the velocity of the crack v → 0, the moving PS model will reduce to the static PS model. When the size of the electric saturation zone r → 0, the moving PS model is in agreement with the moving linear piezoelectric model.

S. Tse

Papers

Moving Griffith crack in an orthotropic material