Predicting the fracture trajectory in U, VO, and key-hole notched specimens using an incremental approach

In this paper, an incremental approach is proposed for predicting the fracture trajectory in specimens containing U, V with end hole (VO), and key-hole shaped notches. In this approach, the first initiation angle of crack is calculated from the maximum tangential stress (MTS) criterion corresponding to stress field around the notch border. Then, a short crack is generated from notch border along the calculated fracture angle. The next step is to obtain the fracture initiation angle for the new cracked sample using the MTS criterion formulated according to the stress field at the vicinity of the crack tip. This procedure is repeated until the crack reaches the back boundary of the specimen. The proposed method is evaluated by means of various experimental results reported in the previous studies for three sets of experiments conducted on the Brazilian disks containing the U-shaped, VO, and key-hole notches under mixed mode I/II loading. It is shown that the fracture paths predicted by the proposed approach are in good agreements with those obtained from the broken samples.