Finite crack kinking and T-stresses in functionally graded materials

摘要: Abstract The optimum direction of in-plane continuous crack advance in functionally graded materials (FGMs) is discussed. FGM modeled using finite element analysis as a linear elastic material with spatially varying Young’s modulus. kink was determined the angle at which either energy release maximized ( G max ) or tip deformed without shear K II =0). Results are found to asymptote toward that from infinitesimal short analyses for homogeneous materials, based on local gradient-adjusted phase but only very kinks. systematic discrepancy between and results can be accounted by including effect apparent parallel T -stress. This -stress affected both far-field loading and, unlike angle. magnitude is, average, greater than identical geometry comprised material. For lengths same order gradient dimension greater, there divergence angles two criteria. In addition, bifurcation negative angles. caused competition near-tip -dominant field nonsingular gradient-induced terms, which, turn, reflects differing effects tendency move more compliant region within modulus gradient.