Hot spot and volumetric approaches to the high cycle fatigue of notched components
The high cycle fatigue of notched components traditionally is examined using the so-called hot spot approach. This relatively old approach is based on the concept of the fatigue stress concentration factor and the fatigue sensitivity index. It requires empirical relationships between fatigue sensitivity index and notch radius. The more recent volumetric approach is based on the fact that the fatigue mechanism needs a physical volume. Inside this volume, the average stress or effective stress plays the major role. This effective stress is introduced in the fatigue resistance relationship in order to compute the fatigue life duration.