Prediction of fatigue crack initiation life of aluminium alloy joints using cyclic elasto-plasticity FEM analysis

Abstract

Finite element analyses (FEA) are particularly useful for investigating fatigue problems since it is possible to carry out elasto-plastic simulations for any configuration and to predict the material behaviour for a large number of loading cycles. This study aims to investigate the fatigue life for Al-Mg alloy A5083-O joints by means of numerical simulations. The Proposed method needs to give a precise description of the elasto-plastic behaviour of the alloy together with an appropriate definition of the criteria for the fatigue crack initiation. In this paper, the elasto-plastic behaviour of the A5083-O alloy was investigated by FE analyses. On the other hand, the fatigue crack initiation criterion is provided based on strain ranges observations. In detail, the finite element analyses focused the attention on the study of the service life of a butt-weld join.