Elastic-Plastic Fracture Mechanics Model for PlanarIsotropic Porous Materials with Small Mixed-Mode Cracks

摘要

A porous panel with a small crack subjected to mixed-mode loads under yielding and plane stressconditions is examined here. The recently proposed modified Gursons yield criterion is adopted to toaccount for the non-linear behavior of a porous panel with normal anisotropy but planar isotropy.Trends in the constant J contour, based upon a finite element analysis, are correlated with those ofconstant fatigue life contours under mixed-mode I and II loading conditions. The effects of both theanisotropy parameter and the porosity upon the J integral are then demonstrated. Simulation resultsshow that the transverse strain dominates constant J contours on the -plane as the anisotropyparameter increases under the mixed-mode loads. However, constant J contours are less sensitive tothe transverse strain even if a relatively larger void volume fraction appears in the panel.