This paper considers an anti-plane moving crack between a functionally graded
coating and a homogeneous substrate. The shear modulus and the mass density of
the FGM coating are considered for a class of functional forms for which the
equilibrium equation has an analytical solution. The problem is solved by means of
singular integral equation technique. Results are plotted to show the effect of
material nonhomogeneity and crack moving velocity on the crack tip field. The
angular variation of the near-tip stress field is of particular interest, and
the crack bifurcation behaviour is also discussed. It is shown that choice
of an appropriate fracture criterion is essential for studying the stability
of a moving crack in FGMs. Different fracture criteria could give opposite
predictions for crack stability. It seems that the maximum cleavage stress
near the crack tips is a reasonable failure criterion for a moving crack in
FGMs.
Centre for Advanced Materials
Technology (CAMT)
School of Aerospace, Mechanical and Mechatronic
Engineering
The University of Sydney
Sydney, NSW 2006
Australia
