Two Fatigue Damage Models to Predict Life in SS304 and Al7050 Alloys undergoing Multiaxial Irregular Loading Spectra

Fatigue life of SS304 and Al 7050-T7451 alloys subjected to variable multiaxial loading spectra was evaluatedby means of two energy-based models of (i) Ellyin and (ii) Varvani-Farahani. Total strain energy density per cycle inthe Ellyin model including elastic and plastic strain energies evaluated fatigue life data by using areas within the axialand shear stress-strain hysteresis loops. The Varvani model assessed fatigue lives based on the integration of thenormal and shear energy ranges calculated on the critical plane which was determined through the largest stress andstrain Mohr’s circles. Wang-Brown multiaxial cycle counting method was employed to count the reversals overvariable multiaxial loading spectra. The assessment of fatigue lives based on the Ellyin, and Varvani damage modelsshowed good correlations with experimentally obtained life data.

کلیدواژه ها:

Multiaxial irregular loading ، Cycle counting ، Energy-based models ، Fatigue damage ، Life prediction