Fatigue Damage Accumulation Model of 6082-T6 Aluminum Alloy in Conditions of Block Bending and Torsion

This article presents a comparison of damage accumulation calculations performed according to the Palmgren-Miner linear damage hypothesis and a new nonlinear damage accumulation aggregation hypothesis based on material memory for completed experimental block tests of 6082-T6 aluminum alloy. Block loads represent operating runs by way of application in proper sequence blocks with the specific number of cycles of the sinusoidal course. Depending on the combination chosen, the duration of the first block was 20, 40, or 60 % of the base number of cycles Nf and of the second block until damage. Block tests were carried out for both bending and torsion. Moreover, the article contains a review of the newest proposals regarding the assessment of fatigue damage accumulation. The results obtained from calculations of the analyzed two hypotheses of fatigue damage accumulation have been compared with the calculations of a damage degree for random loading. During the analysis of the average values obtained, it may be observed that the authors’ new proposal gives better results.