Experimental and theoretical fracture analysis of quasi-brittle polymer components containing V-notches with end holes under combined tensile-shear loading

In the present investigation، first، 48 fracture tests were conducted on the Brazilian disk specimens made of the quasi-brittle polymer Polymethyl-methacrylate and weakened by central V-notches with end holes (VO-notches) under combined tensile-shear loading with different mode mixity ratios. The fracture loads and the fracture initiation angles (FIAs) were experimentally measured. Then، two brittle fracture criteria were developed on the basis of the failure concepts of the maximum tangential stress (MTS) and the mean stress (MS) for predicting the experimental fracture loads and the FIAs، and the theoretical results were obtained in the form of the fracture curves and curves of fracture initiation angle. A very good agreement was shown to exist between the theoretical and the experimental results. Moreover، it was found that both the criteria provide almost identical predictions to the experimental results.