Abstract:

ESDU 84025 provides a method for estimating the fatigue endurance of the lugs under a constant amplitude alternating load. The results of over 800 tests taken from the literature were analysed; graphs show the test results, with design S-N curves, plotted in terms of non-dimensional parameters that account for the effects of alternating and mean stress, stress concentration, interference-fit, and material characteristics through ultimate tensile strength. Data cover Al-Cu-Mg and Al-Zn-Mg alloys in three heat treatments. Tables detail the material specifications and the lug geometries tested. Pin, or bush, diameter-to-lug thickness ratios ranged from 0.16 to 1.71. The effect of interference-fit on the local tensile stress and fatigue alternating stress on the hole boundary is discussed.