Averaged strain energy density estimated rapidly from the singular peak stresses by fem under (I+II) and (I+III) mixed mode conditions

The strain energy density (SED) averaged over a control volume of radius R0 proved to con-trol fracture and fatigue behaviour of different materials in many engineering problems. The present contribution reviews a recently proposed method to rapidly estimate the averaged SED at the tip of cracks under in-plane I+II and out-of-plane I+III mixed mode loadings. It is based on the peak stresses evaluated from finite element (FE) analyses, according to the peak stress method (PSM). The advantage of the proposed approach is two-fold: there is no need of mesh refinements in the close neighbourhood of the points of singularity, so that coarse FE meshes can be adopted; moreover, geometrical modelling the control volume in FE models is no longer necessary.