Damage in the complex low-cycle fatigue

A life prediction approach for a random multiaxial fatigue is proposed in the present paper. D16T aluminium alloy were tested under non-proportional loading (tension-compression, torsion). Cylindrical specimens were tested under different stress controlled trajectories in the plastic range. In additional, numerical method analysis such as finite method – FEM were used in the experiment. The additional damage energy for Al alloy D16T in the middle stabilized (average) cycle during low cycle fatigue for complex non-proportional loading square trajectory was also discussed in relation with fatigue life prediction.The aim of this paper is to examine the non-proportional low cycle fatigue life of D16T aluminium alloy which shows small additional damage stress, and also develop energetically damage model for complex non-proportional stress state during low-cycle fatigue for construction.