Prediction of the Fatigue Life with the Finite Element Method

A postprocessor program for the calculation of the fatigue life of components calculated with the finite element method (FEM) is described. Based on the stresses calculated by FEM and the material data of unnotched test specimens, s/n curves in relation to FE nodes are calculated for components taking into account the most varied influencing factors, such as amplitude stress tensor, mean stress tensor, relative stress gradient, surface roughness, technological influences, local plastic deformations etc. The results of the calculations, such as damage distribution and insusceptibility to permanent rupture, are graphically represented in the form of FE colour plots. Besides the possibility of the calculation of the fatigue life of components also costs and time can be reduced during the development phase of vehicles.