The paper establishes a relationship between the solutions for cracks located in the isotropy plane of a transversely isotropic piezoceramic medium and opened (without friction) by rigid inclusions and the solutions for cracks in a purely elastic medium. This makes it possible to calculate the stress intensity factor (SIF) for cracks in an electroelastic medium from the SIF for an elastic isotropic material, without the need to solve the electroelastic problem. The use of the approach is exemplified by a penny-shaped crack opened by either a disk-shaped rigid inclusion of constant thickness or a rigid oblate spheroidal inclusion in an electroelastic medium Keywords: transversely isotropic piezoceramic medium, plane crack, rigid inclusion, isotropy plane, penny-shaped crack, disk-shaped rigid inclusion of constant thickness, oblate spheroidal inclusion, stress intensity factorIntroduction. Methods to solve three-dimensional problems of elasticity for bodies with cracks are well developed. Results on stress intensity factors (SIFs) for cracks in an elastic medium are presented in numerous publications [3, 7, 8, 15, 19, 21, etc.]. The brittle fracture of prestressed bodies is studied in [2]. The extensive use of piezoceramic materials, which are distinguished by considerable brittleness, necessitates studying the mechanical and electric fields around stress concentrators such as cavities, inclusions, and cracks in electroelastic bodies [1, 4-6, 9-14, 6-18, 20, 22-24]. However, solving electroelastic problems involves severe mathematical difficulties compared with elastic problems because the original equations for electric and strain states constitute a more complicated system of differential equations [1,4]. The homogeneous equations of electroelasticity for piezoceramic bodies are addressed in [5,22].The present paper establishes a relationship between the solutions of the three-dimensional problem for plane cracks opened by rigid inclusions in an elastic isotropic space and in a transversely isotropic electroelastic medium. It is assumed that the crack is in the isotropy plane of the transversely isotropic electroelastic material and there is no friction between the crack and the inclusion. Thus, we can calculate the stress intensity factor (SIF) K I in a piezoceramic space from the expressions for the SIF in an elastic isotropic medium with a plane crack and a rigid inclusion of the same shape, without the need to solve the electroelastic problem. As examples of using such a relationship, we will consider a penny-shaped crack opened by either a rigid disk-shaped inclusion of constant thickness or a rigid inclusion in the form of an oblate spheroid in an electroelastic space.
Problem Formulation and Basic Equations.Consider a three-dimensional transversely isotropic electroelastic space with a system of plane cracks (occupying a domain S ) located in a plane perpendicular to the polarization axis and opened by rigid inclusions (occupying a domain S 1 , i.e., S S 1 Ì ). The free portions of the cracks are not sub...