A DUGDALE-TYPE ESTIMATION OF THE PLASTIC ZONE FOR A PENNY-SHAPED CRACK IN A THICK TRANSVERSELY ISOTROPIC LAYER DUE TO RADIAL SHEAR

A penny-shaped crack is considered under the action of radial shear in a thick transversely isotropic elastic layer. The external faces of t he layer are stress free. Employing the Dugdale hypothesis and Hanker transform theory, the problem of determining the size of the plastic z one is reduced to the numerical solution of a Fredholm integral equati on of the second kind. Graphical results showing the effect of transve rse isotropy upon the width of the plastic zone are presented and comp ared with results obtained for isotropic material.