INFLUENCE OF CORRELATIONS BETWEEN STRESSES ON CALCULATED FATIGUE LIFEOF MACHINE ELEMENTS

The correlation between components of the random stress tensor and its influence on the calculated fatigue life of machine elements were ana lysed. Three covariance matrices of components of biaxial stress state were considered. They were determined from measurements of strains in an element of a vibrating screen for aggregate, in the back wall of a bus, and in a welded element of excavator fittings. Calculations were made according to four criteria of multiaxial random fatigue. Cycles were counted with the rainflow method, and damage was cumulated with t he Palmgren-Miner hypothesis. It was found that convariances of random stress state components strongly influence the calculated fatigue lif e. Copyright (C) 1996 Elsevier Science Limited.