Assessment of Fatigue Behavior and Effects of Crack Growth in Aluminium Alloys 6082 under Various Stress Ratios

The purpose of this study is to investigate the fatigue behaviour of the aluminium alloy 6082 by a finite element analysis (FEA). The tests are released for various specimens subjected to cyclic tensile loading in order to characterize the damage evolution and the fatigue strength of the aluminium alloy 6082. The results show the Wöhler curves (S-N curves) for the tested specimens under various stress amplitude levels and for different stress ratios values (R=0, R=0.5, R=-1). The obtained data highlights the strong influences of the stress ratios R and the effects of high cyclic loading on the decreasing of aluminium alloys 6082 life and performances. Afterward, fatigue crack growth under tensile loading was investigated, in this way fatigue tests have been performed on specimens with different pre-cracks sizes to underline the influences of the crack growth on the lifetime and fatigue behaviour of the tested specimens. The predicted fatigue life and the results obtained for the different loading conditions presented in this study were found to be in good agreement with the experimental fatigue investigations published in the literature