An Evaluation of Simplified Methods to Compute the Mechanical Steady State

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

The accuracy of the fatigue prediction in low cycle fatigue (LCF) relies on the quality of the crack initiation model, but also on its input. It is then crucial to have a good method to evaluate the mechanical steady state of stresses and strains of the structure. Due to the increasing power of the computers, one can now in some cases run the full computation, for instance with several hundreds of cycles, until a periodic state is reached. This solution may be not adequate when the structure is too big, or when one needs a very quick computation, especially for parametric studies. The purpose of the paper is then to study several techniques providing a direct access to the numerical steady state, and to give a critical review of their performances. Three types of methods will be considered: Zarka's method; cycles skip and the direct cyclic method.