HYGROTHERMAL STRESSES FOR A PLANE CRACK IN A GENERALLY ANISOTROPIC PLATE

The solutions are presented for the hygrothermal stress field of a generally anisotropic plate under uniform heat flux and moisture concentration transfer obstructed by a hygrothermally insulated crack. For uncoupled diffusion of temperature and moisture, the solutions of both temperature and moisture are obtained directly from the Hilbert problem approach, and are treated as the particular solutions to a pair of nonhomogeneous partial differential equations for an uncoupled hygrothermoelastic system. The associated homogeneous solutions are expressed in terms of three stress functions based on the complex variable approach of Lekhnitskii. With some identities concerning the eigenvalues and eigenvectors, the general expressions of the stress and displacement fields can then be found in an explicit form. The stress intensity factors, crack opening displacements and energy release rate are expressed in terms of the heat flow, moisture concentration, material geometry, elastic and hydrothermal anisotropy. The simultaneous existence of mode I, II and III fracture is found to be due to material inherent anisotropy. Special cases for isotropic and orthotropic materials are also discussed.