Fracture analysis of functionally graded materials with U- and V-notches under mode I loading using the averaged strain-energy density criterion

One of the most powerful criteria to predict the critical fracture load in plates with notches is the strain-energy density averaged over a well-defined control volume ahead of the notch tip. Although the averaged strain-energy density (ASED) criterion has been proposed for homogeneous materials, it has been shown in this paper that this criterion can also be applied for non-homogeneous materials, especially for functionally graded materials (FGMs). A numerical method has been used to evaluate the control volume boundary, the averaged strain-energy density over the control volume, and also the critical fracture load in FGMs under mode I loading. A new set of experimental results on fracture of blunt V-notched samples made of austeniticmartensitic functionally graded steel under mode I loading have been provided.