Critical issues in high cycle fatigue

High cycle fatigue (HCF) failures in materials used in rotating components of gas turbine engines have often been found to be attributable to fatigue loading on materials which have sustained damage from other sources. Damage can be present in the form of initial material or manufacturing defects, o r can develop during service operation. Three major sources of in-service d amage have been identified which can alter the HCF resistance individually or in conjunction with one another: low cycle fatigue (LCF), foreign object damage (FOD), and fretting. Methodologies for treating such damage in esta blishing material allowables are considered. Some recent results on the eff ects of damage on the Haigh (Goodman) diagram and a discussion of the life management aspects of HCF are presented. (C) 1999 Published by Elsevier Sci ence Ltd. All rights reserved.