A generalized three-parameters model to describe the strain-life curve under asymmetrical cyclic loading Ein verallgemeinertes Drei-Parameter-Modell zur Beschreibung der Dehnungs-Lebensdauer-Kurve unter asymmetrischer zyklischer Belastung

Abstract

It is widely known that the mean stress has substantial influence on fatigue life of material under asymmetrical loading. Hence, it is important to take into account the mean stress effect in fatigue life prediction. In this work, an equivalent strain amplitude that is similar to the Smith-Watson-Topper's parameter was proposed by introducing the mean stress term. The new strain-life model resulting from the proposed equivalent strain amplitude can be used to correlate the uniaxial fatigue data under both symmetrical and asymmetrical cyclic loadings. Extensive experimental validations using 394 data sets from 10 metals collected from the literature show that the established model can provide good estimations for the loadings with various mean stresses, including compression-compression cyclic loading.