Fracture Assessment of Blunt V-Notches under Prevalent Mode II Loading by Means of Local Energy

The main purpose of this research is to re-analyse experimental results of fracture loads for blunt V-notched samples under mixed mode (I+II) loading considering different combinations of mode mixity ranging from pure mode I to pure mode II. The specimens are made of polymethyl-metacrylate (PMMA) and tested at room temperature. The suitability of fracture criterion based on the Strain Energy Density (SED) when applied to these data is checked in the paper. Dealing with notched samples, characterized by different notch angles and notch root radii, the SED criterion used in combination with the concept of local mode I, valid in the proximity of the zone of crack nucleation, permits to provide a simple approximate but accurate equation for the SED evaluation in the control volume.