An improved procedure for component life estimation with applications.

Abstract

A general procedure is described for the calculation of fatigue initiation life. This procedure was developed for the investigation of component fatigue failure, but it is also suitable for the design of new components. The procedure incorporates the effects of steady stresses, dynamic stresses from excitation spectra, and material cyclic properties. The Rainflow cycle counting procedure is used to incorporate complex response waveforms, and the Local Strain approach is used to determine the amount of fatigue damage from each harmonic component. The resulting cumulative damage is evaluated using Miner's law, to provide an estimate of component life under given stress and thermal load conditions. Several examples which describe the application of this procedure are given. (A)