A continuum damage mechanics model with the strain-based approach to biaxial low cycle fatigue failure

A continuum damage mechanics model for low cycle fatigue failure of initial ly isotropic materials under biaxial loading conditions is presented. The e xpression for the equivalent strain in the fatigue damage evolution equatio n contains the three material parameters, and the strain intensity as well as the maximum principal strain and the volume strain for amplitudes. It is shown how these material parameters can be determined from a series of bas ic experiments using a cruciform specimen. Particular expressions for the e quivalent strain with a smaller number of material parameters and invariant s are obtained. Model predictions are found to be in satisfactory agreement with the experimental low cycle fatigue data under full ranged biaxial loa dings obtained in the test using a cruciform specimen.