ABSTRACT
In this study the axisymmetric crack problem in a functionally graded semiinfinite medium is considered. It is assumed that the penny-shaped crack is located parallel to the free surface and the mechanical properties of the medium vary in depth direction only. By using a superposition technique the problem is reduced to a perturbation problem in which crack surface tractions are the only external forces. The corresponding mixed boundary value problem is then reduced to an integral equation with a generalized Cauchy kernel and solved numerically to obtain stress intensity factors and crack opening displacements. Results obtained for different nonhomogeneity and length parameters are presented and discussed. The problem has applications to the investigation of the general question of spallation fracture.
