A User's View of Fatigue Life Predictions

Recent advances in metal fatigue analysis are examined with a view toward the need to devise specific procedures for acquiring and processing strain or load histories in order to evaluate structures for in-service fatigue life. Emphasis is on location of waveform reversal points, omission of insignificant ranges, and on cycle identification. A damage and life calculation method is selected and used as an example around which to construct a complete procedure for prediction of crack initiation life from strain histories; alternatives are considered. A method of estimating the cyclic stress-strain curve is proposed.