Multiaxial high-cycle fatigue criterion for hard metals

Some multiaxial high-cycle fatigue criteria based on the so-called critical plane approach are reviewed. According to such an approach, the critical plane where the fatigue life assessment should be performed can be determined by maximising the amplitudes and/or values of some stress components. In the present paper, the critical plane orientation is correlated with the averaged principal stress directions deduced through the weight function method, and a new fatigue failure criterion is proposed. The results derived by applying the present criterion and the other critical plane criteria analysed are compared with experimental data related to different brittle (hard) metals under in-phase or out-of-phase sinusoidal biaxial normal and shear stress states.