T-stress effects in mixed mode I/II/III brittle fracture

• Generalized maximum tangential stress criterion is extended to mixed mode I/II/III.
• T-stress effects on fracture parameters are explored for mixed modes I/III and II/III.
• Effect of T-stress in pure mode III fracture is lower than in pure mode II fracture.
• The results of extended criterion are dependent on the value of Poisson’s ratio.

The generalized maximum tangential stress (GMTS) criterion proposed in the past for brittle fracture under mixed mode I/II loading is extended to mixed mode I/II/III. The theoretical predictions of the extended criterion were validated by some experimental results reported in literature but only for in-plane loading. Then, the effects of T-stress on the fracture resistance and also on the in-plane and out-of-plane fracture angles are explored in mixed modes I/III and II/III. It is shown that the results of extended criterion depend on the T-stress, the Poisson’s ratio and also on whether the crack problem is plane stress or plane strain. Despite the considerable influence of T-stress on the fracture behavior in pure mode III, its effect is lower than that of pure mode II.