Abstract:

The pull-pull low cycle fatigue test is conducted for various specimens made from GH33A steel. There are three forms of the specimens: the cylindrical bar, the drum-form plate and the plate with a centre circular hole. The fatigue life measured experimentally is compared with one predicted by using local stress-strain approach. As the stress concentration factor is increased, the ratio of test life to predicted life is raised. According to the Miner law,the damage caused by one overload can be neglected. But experimentally an overload results in a considerable reduction in low cycle fatigue life. Owing to two-directional stress-strain status at a notch of the thicker plate, the fatigue life of the thicker specimens is longer than that of thinner plate. In general, the low cycle fatigue life predicted by the local stress-strain approach agrees well with experimental results.

Key words: low cycle fatigue, fatigue life prediction, fatigue test