A strain energy density design approach for large cast iron components: From microstructural analysis to multiaxial fatigue response

A new criterion for predicting multiaxial fatigue in plain and V-notched specimens made of ductile cast iron is proposed. The criterion is based on volumetric strain energy density (SED) and separately accounts for the effect of normal and shear mean stresses with two material-dependent coefficients. The criterion also considers the impact of out-of-phase loading through a strengthening factor, assuming that fatigue damage is initiated by the total SED peak in the cycle. The criterion is validated using a large amount of independent multiaxial fatigue data, obtained from testing three different ductile cast iron grades.