Detection of fretting fatigue crack initiation by thermography

Three fretting fatigue tests under partial slip conditions are monitored using an infrared camera to detect crack initiation of the fatigue samples prior to final failures. 10 thermal images per fatigue cycle are captured for a period longer than calculated number of cycles of crack propagation before failures. After failures, temperatures evolution at maximum fatigue load of 4 zones of interest are analyzed during this period. The temperatures of all zones of interests reach a stabilization before a thermal indication of crack initiation.