Finite element evaluation of stress intensity factors in curved non-planar cracks in FGMs

In this work the mixed mode stress intensity factors (SIFs) of three-dimensional curved non-planar cracks in functionally graded materials (FGMs) are analyzed using the interaction energy integral. In particular, the finite element method is employed to extract the SIFs along the front of a lens shaped crack in a FGM. In order to cross check the capabilities of the present implementation, material gradation is reduced to zero and the numerical results are in turn compared to the analytical solutions for SIFs available for homogeneous materials. Finally, the contribution of material gradation to the SIFs is explored considering exponential spatial variations for Poisson’s ratio as well as for Young’s modulus.