In the classical crack-tip stress field

the singular stresses (r1/2 term) near the crack tip are characterized by a single parameter

i.e. the stress intensity factor K. Therefore

the O(r1/2) term and the secondary non-singular term (T-stress) are always ignored. However

the stress and strain fields around the crack tip are influenced considerably by the T-stress. In this paper

the conventional fracture growth criteria

i.e. the maximum tangential stress criterion is modified to take into account the effect of T-stress

and is used to study the fracture growth when subjected to modes I

II or mixed mode (I/II) loading. The results show that: (1) In the pure mode I loading condition

if the T-stress is negative (compression)

the crack growth is stable. However

if the T-stress is positive (tensile)

the crack grows along the crack direction only when

otherwise

the crack growth direction will be changed. (2) In the pure mode II loading condition

the crack growth direction and the loading capacity are influenced not only by the stresses along the fracture direction (T-stress) but also by the normal stress on the fracture. (3) For the mixed loading condition

the T-stress consideration in the fracture criteria leads to better agree with the experiments. The positive T-stress results in an increase in crack growth angle

while the negative T-stress decreases that angle. The results reveal that it is benefit to control the T-stress to change the crack growth direction

in order to avoid the most dangerous crack growth direction or stopping/slowing down the overall structural fracture.