Abstract
The evaluation of the fatigue limit is important in designing products. Fatigue limit estimation based on dissipated energy has been getting considerable attentions. In this method, temperature change due to irreversible energy dissipation is measured by infrared thermography for various levels of stress amplitude. It is known that the dissipated energy increases with increasing stress levels, and a certain stress level where the change in dissipated energy shows sharp increase coincides with fatigue limit. In this study, this technique was applied to the detection of crack initiation location. The fatigue limit estimation and fatigue tests were carried out for the specimen having multiple notches. It was found that the increasing rate of dissipated energy measured at the notch where crack was initiated was larger than that at other notches. Therefore, it was considered that the location of crack could be detected before crack initiation by using dissipated energy measurement.
