A NEW TECHNIQUE FOR THE FATIGUE LIFE PREDICTION IN NOTCHED COMPONENTS

Créé le : 13/09/2010 - Mis à jour le : 15/11/2012

After pointing out the limitations of the classical Neuber type methods, we propose a new procedure for calculating fatigue life of notched components. It includes a new approach for accelerate devaluation of stress and strain histories at the notch tip. A methodology coming from the study of uniform fields models is used to describe the evolution of the residual stresses at the notch tip. A tensorial variable allows us to take into account the stress redistribution around the notch tip. The model is calibrated by two short FEM computations of the component representing a monotonic preload of the structure, first with the elastic behaviour, then with the real elasto-plastic behaviour. These computation results are used to determine the parameters of the transition rule, which allows to simulate the whole loading history.The local stress histories are then treated through a new multiaxial rainflow cycle counting algorithm. Contrary to classical rainflow algorithms that count an equivalent variable, it takes into account the whole stress tensor...