Application of a new model proposal for fatigue life prediction on notches and key-seats

The aim of this paper is to introduce a new macro-mechanical model for fatigue life prediction, taking into consideration an elastic-plastic stress distribution and the stress gradient evolution. Mainly based on the stress field intensity approach, this new model tries to better take into account the role of the most important factors influencing the fatigue failure process. A very brief review of some previous models facilitates the comparison between these approaches and fatigue test results obtained on notched specimens with two different radii. A description of the stress field intensity model is then given, followed by the new model in more detail. In order to better verify the fatigue life prediction given by this method on another kind of notch geometry, a comparison between the method and test results on the rotating bending of specimens with key-seats, is carried out. In all cases, the fatigue life predictions obtained by use of this method, are in very good agreement with the respective test results. (C) 1999 Elsevier Science Ltd. All rights reserved.