抄録
Statistical fatigue testing based on JSME S 002 was conducted on test pieces prepared from the nodular iron casting of the crank shaft of a diesel engine using a rotating fatigue test machine. In order to clarify causes of scatters of fatigue strength and fatigue life, the distribution of the size of micro cracks was examined. The scatter in long term life was controlled by crack coalescence, while the scatter in short term life was defermined by √(area of abnomal graphite).
