Author(s)

D.G. Pavlou

Abstract

A damage tolerance analysis methodology for cracks subjected to real loading is presented. A new retardation model, based on material hardening within the overload plastic zone, is developed for irregular stress histories. For the transformation of the irregular stress history into a stress history containing only distinguished cycles, a technique based on the Rainflow counting method is used. The methodology is applied to real aircraft loading histories for the conventional 2024-T3 aluminum and the advanced 8090-T8 aluminum-lithium alloy. Predictions are in encouraging agreement with the experimental results. Limitations of the prediction method are also discussed. 1 Introduction Aerospace structures are operating under highly variable fatigue conditions. Up to present, fa

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