Evaluating MTS criterion in predicting mixed‐mode crack extension under different loading conditions.

The maximum tangential stress (MTS) criterion is one of the most widely used criteria for predicting the direction of crack extension. The suitability of this criterion is examined under different loading conditions using the extended finite element method (XFEM). Experimental and numerical results reported in the literature are considered to evaluate the validity and accuracy of the criterion. The results demonstrate that the MTS criterion evaluated by stress intensity factors (SIFs) can accurately predict the direction of crack propagation in specimens under direct tensile loading. This criterion overestimates the angle of crack initiation in the specimen under indirect tensile loading but underestimates the angle in the specimen subjected to 3‐point bending. It is concluded that the MTS criterion based on SIFs could not accurately predict the direction of the crack initiation, which could, however, be determined properly based on the stress distribution around the crack tip obtained by the XFEM numerical models. HIGHLIGHTS: The suitability of the MTS criterion is examined under different loading conditions.Under indirect tensile loading, the MTS criterion overestimates crack initiation angle.The MTS criterion underestimates the angle in the specimen under 3‐point bending.Initiation angle can be predicted properly based on stress distribution around crack tip. [ABSTRACT FROM AUTHOR]