Stress and fatigue analyses of an induction hardened component

Stress analysis of an induction hardened shaft subjected to cyclic torsional loading is conducted. Finite difference method is employed with the application of an Armstrong-Frederick type cyclic plasticity model. Predictions of residual stresses and their relaxation agree well with the experimental observations. Fatigue is,. analyzed using the results from the stress analysis. Three critical plane multiaxial criteria are evaluated. Due to the variation of material properties and residual stresses, failures can be initiated at surface and subsurface sites. The shear based fatigue parameters can correlate the experimentally observed fatigue lives as well as the crack initiation locations. It is noted that it is critical to consider the residual stresses and the residual stress relaxation in the fatigue life prediction for the induction hardened shafts.