Abstract:

ESDU 80007 provides estimates of the fatigue endurance of aluminium alloy lugs with push-fit pins subjected to alternating loads. The results of 1740 fatigue tests have been analysed and are presented graphically by plotting the endurance (i.e. cycles to failure) against non-dimensional parameters for both the applied alternating and mean stresses that take into account the effect of the geometric stress concentration factor of the lug and the ultimate tensile strength of the alloy. Mean curves are drawn through the data to give design S-N curves for various types of lugs and materials. Data for both Al-Cu-Mg and Al-Zn-Mg alloys in three heat treatment conditions, namely artificially aged, cold worked and artificially aged and naturally aged, are presented and the effect of variations in pin diameter on the fatigue endurance illustrated. The geometry of all the lugs analysed is presented in a series of comprehensive tables and covers lugs with thickness/pin diameter ratio ranging from 0.33 to 1.64. The data are particularly relevant to aircraft wing spar root joints, store attachment points, etc.