ABSTRACT
To determine the stress and strain at notch root of the welded structures, the cyclic stress strain curve, in the form of Ramberg-Osgood equation, and the macrostructure support formula proposed by Neuber, also known as Neuber’s rule, is widely used (Newport & Glinka, 1990). The frequently adopted method to obtain cyclic stress strain curve is the single-step or companion sample method, the multiple-step method and the incremental step method under uniaxial strain controlled loading. The tips of the stable hysteresis loops are connected to form the cyclic stress strain curve. Conventionally half-life in single step method is taken as the stable state of hysteresis loops. It has been proved that saturation of plastic strain energy per cycle is an effective criterion of stable state (Li et al., 1997).
