Reduction of the Endurance Limit as a Result of Stress Interaction in Fatigue
Report Number: WADD TR 60-752 Author(s): Robert A. Heller Corporate Author: Columbia University Laboratory: Materials Central Date of Publication: 1961-02 Pages: 33 Contract: AF 33(616)-7042 Project: 7351 - Metallic Materials Task: 73521 AD Number: AD0258024Contrails does not possess a copy of this report. Click here to offer Contrails a donation of this report
Abstract: This paper presents the results of an investigation of the effects of stress interaction on fatigue life of aircraft structural materials subjected to randomized load spectra. All three materials: 2024 and 70?5 aluminum and SAE 4340 steel exhibit fatigue lives shorter than those predicted on the basis of the linear (Miner) damage rule. A quasi-linear rule is proposed with a variable, spectrum dependent. endurance limit producing safe life estimates; the dependence of the endurance limit on the stress spectrum and its resulting design inadequacy is shown. Tests were performed on high speed, programmed, rotating bending fatigue machines of special design.