Fatigue life prediction under mean stresses using critical plane approach

Abstract

This paper suggests that multiaxial fatigue criteria can serve as damage parametersin the formulation of critical plane theory. We propose that by incorporatingstrain rate effects, critical plane approximation parameters can be effectivelyused to estimate fatigue life under various test conditions. Unlike the classicalapproach, this improvement offers the advantage of building the parameter versuslife relationship, regardless of the type of test used for calibration. To definethis new relationship, we present a calibration strategy that considers criticalplane models based on the Fatemi-Socie and Smith-Watson-Topper criteria. Theaccuracy of the method is verified using data sets extracted from the literature.A study on the impact of the stress ratio on the parameter versus life curve isincluded, indicating that although the relationships obtained depend on the valueof the stress ratio (R) used in the calibration, the life predictions derived fromthese relationships are statistically similar.