Application of modified fracture criteria incorporating T-stress for various cracked specimens under mixed mode I-II loading

Accurate assessment of fracture behavior and life prediction of cracked materials based on the mixed mode fracture criteria is of utmost importance in fracture mechanics. In this study, the modified fracture criteria incorporating T-stress for mixed mode I-II cracks were comprehensively reviewed. Additionally, a comparative analysis was conducted between the experimental results obtained from five different cracked configurations and the theoretical predictions according to these modified criteria. Moreover, a brief discussion was held regarding the effect of T-stress on both crack initiation angle and fracture toughness, accompanied by providing some suggestions. The results revealed that the predictive accuracy of modified criteria exhibited noticeable variations across different cracked configurations due to the significant disparities in both the sign and magnitude of Tstress around the crack tip. However, it was observed that the predicted curves based on the modified fracture criteria for the semi-circular bend and edge-crack triangular specimens had remarkable similarities owing to their similar biaxial stress ratio B. When the mode II loading dominated, the generalized maximum tangential stress, generalized minimum strain energy density and generalized averaged strain energy density criteria were suitable for the semi-circular bend, edge-crack triangular, central crack rectangular and short bend beam specimens with positive T-stresses, whereas the maximum tangential strain, generalized maximum tangential stress and generalized maximum tangential strain energy density criteria could provide better theoretical predictions for central cracked Brazilian disk specimens having a negative T-stress.

Automated summary

Accurate assessment and prediction of fracture behavior in cracked materials using mixed mode fracture criteria are crucial in fracture mechanics. This study comprehensively reviewed modified fracture criteria that incorporate T-stress for mixed mode I-II cracks. A comparative analysis was conducted between experimental results and theoretical predictions for five different cracked configurations. The study also discussed the effect of T-stress on crack initiation angle and fracture toughness, providing suggestions. The results showed variations in predictive accuracy across different cracked configurations due to disparities in T-stress. However, similar predictions were observed for semi-circular bend and edge-crack triangular specimens due to their similar biaxial stress ratio B. Different fracture criteria were suitable for different cracked configurations with positive or negative T-stresses.