A mean stress correction model for tensile and compressive mean stress fatigue loadings

Abstract

A new mean stress fatigue model based on the distortional strain energy is proposed to account for the mean stress effects on fatigue life. The proposed model is compared with the Morrow and the Smith‐Watson‐Topper (SWT) mean stress correction models using a number of experimental data sets for one cast iron, two steels and two aluminium alloys under tensile and compressive mean stress loadings. It is found that both the proposed mean stress correction model and the SWT model yield similar results and provide very good correlation for positive mean stress data and moderate negative mean stress data. For high compressive mean stresses, the proposed model shows reasonably good correlations, while the SWT model fails to correlate the fatigue data. The Morrow model was found to give poor correlations for all fatigue data analysed by yielding conservative results for compressive mean stresses and non‐conservative results for tensile mean stresses.

Mean stress effect on Gaßner curves interpreted as shifted Wöhler curves and application to smooth and notched geometries

“…Despite this, since the SWT correction is being used, such ratio may lead to unconservative life predictions for highly negative mean stresses. Therefore, this sort of nonconservativity is expected for the Suspension spectrum, and it would be consistent with the findings of Ince and Glinka, Kujawski, and Ince . (d) A higher Basquin law exponent k tends to lower the G −1/ k ; this effect can be noted by comparison of the two different materials, with Man Ten, which provides higher values of G −1/ k .…”

“…As regards RQC‐100, almost all the predictions seem to be collocated on the conservative side of the bisector, whilst for Man Ten predictions are simply within the scatter bands. The slight nonconservativity observable in the predictions for Suspension spectrum (eg, SM4 specimen in Figure ) confirms what observed by Ince and Glinka, Kujawski, and Ince . Notwithstanding, since all the predictions lie in the typical scatter bands, the adoption of a modified SWT model does not seem necessary in this case.…”

“…of Ince and Glinka or fig. of Ince, more sophisticated models based on SWT or Walker do not provide significant overall improvements on the life prediction accuracy.…”

Structural reliability analysis and uncertainties‐based collaborative design and optimization of turbine blades using surrogate model

“…To improve the performance of blades, it is necessary to analyze the coupling mechanism between shockwave and boundary layer . Many valuable studies have been proposed to perform this analysis by means of numerical simulations combining with physics of failure modeling . Among them, Wang et al utilized a reliability index strategy and proposed an uncertainty‐based optimization model for the structure design problem with bounded uncertain information.…”

A Modified Walker Model Dealing with Mean Stress Effect in Fatigue Life Prediction for Aeroengine Disks

“…Kamaya and Kawakubo [23] investigated the effects of mean stress on fatigue properties of type 316 stainless steel and indicated that mean stress correction was not necessary in component design under load control mode and for constrained ratcheting strain region. Ince [24] proposed a mean stress fatigue model based on the distortional strain energy to account for the mean stress effect on fatigue life for both positive and compressive mean stress conditions. Besides, researchers have proposed many other equations accounting for mean stress effects, some of which are discussed by Nihei et al [25] and Kluger and Lagoda [26].…”