Vol.11, No3, 2011, pp.173–176
UDC 539.422.014

Three types of local fracture criterion are examined: RKR, Beremin and Volumetric method. It can be seen that these criteria are not material intrinsic but depend on constraint effects. To illustrate this problem, the following are shown: dependences of characteristic stress with stress triaxiality, Weibull stress with Q parameter, effective stress with T stress. It is concluded that the use of constraint parameters are necessary to take into account scale, geometric, loading mode and thickness effects on fracture.

Keywords: local fracture criteria, constraint effects