Estimation of crack tip plastic zones in presence of material irregularities by extended finite element method

This work pertains to determine the extent of plastic zones evolved in front of the crack tip in cracked specimens containing different types of inclusions. The analysis has been performed by employing the extended finite element method (XFEM), where discontinuities like cracks, inclusions or holes present in the domain are modeled independent of the mesh. The displacement-based finite element approximations are enriched with additional functions to introduce the effect of discontinuities into the formulation. In order to track the various discontinuities in the domain, level set method is employed. The current study employs XFEM to investigate the assess of size and location of different material irregularities on the amount of plastic zones developed ahead of crack tip in cracked rectangular plates. The mixed mode stress intensity factors have been evaluated by employing the domain-based interaction integral approach. Yield criteria based on Von-Mises and Tresca failure theories have been invoked to estimate the extent of crack tip plastic zones in cracked components. Both plane stress and plane strain conditions have been assumed to investigate the effect of material irregularities on the extent of plastic zones developed ahead of the crack tips.