ISOLATED CRACK IN 3-DIMENSIONAL PIEZOELECTRIC SOLID .2. STRESS INTENSITY FACTORS FOR CIRCULAR CRACK

This is part II of the work concerned with finding the stress intensit y factors for a circular crack in a solid with piezoelectric behavior. The method of solution involves reducing the problem to a system of h ypersingular integral equations by application of the unit concentrate d displacement discontinuity and the unit concentrated electric potent ial discontinuity derived in part I [1]. The near crack border elastic displacement, electric potential, stress and electric displacement ar e obtained. Stress and electric displacement intensity factors can be expressed in terms of the displacement and the potential discontinuity on the crack surface. Analogy is established between the boundary int egral equations for arbitrary shaped cracks in a piezoelectric and ela stic medium such that once the stress intensity factors in the piezoel ectric medium can be determined directly from that of the elastic medi um. Results for the penny-shaped crack are obtained as an example.