Stress intensity factors and energy release rate for anisotropic plates based on the classical plate theory

The stress and displacement fields near the tip of a through crack in an anisotropic elastic plate are examined according to the classical plate theory. The plate is assumed to be subjected to bending moments, twisting moments, or transverse shear forces. In particular, the stresses at the prolongation of the crack and the relative crack face displacements are derived. The results are used to define stress intensity factors which are consistent with those for isotropic material in Ref. [6]. An explicit expression for the energy release rate in terms of the stress intensity factors is obtained using the path-independent J-integral. Analytic solutions are given for the stress intensity factors of a crack in an infinite plate under uniform bending moments, twisting moments, or transverse shear forces. It is shown that the stress intensity factors are zero and the stresses at the crack tip are finite if only twisting moments are applied. A universal relationship between the classical theory stress intensity factors and the Reissner theory stress intensity factors for thin orthotropic plates under symmetric bending is also derived. (C) 2016 Elsevier Ltd. All rights reserved.