Font Size: 

One of the main interests of fracture mechanics in functionallygraded materials is the influence of such an inhomogeneity on a crack propaga-tion process. Using the Griffith’ energy principle, the change of energy has to becalculated, if the crack starts to propagate. In homogeneous linear-elastic structures(asymptotically precise) formulas for the energy release rate are known, but a directtransfer of the methods to functionally graded materials can lead to very inaccurateresults. Moreover, the influence of the inhomogeneity on the crack path can not beseen. Here a simple model for functionally graded materials is presented. For thismodel, a formula for the change of potential energy is derived, giving detailed infor-mation on the effect of the gradation on the crack growth process.