Assessment of fatigue crack closure under in-phase and out-of-phase thermomechanical fatigue loading using a temperature dependent strip yield model

A crack opening stress equation for in-phase and out-of-phase thermomechanical fatigue loading

“…In the previous work [5] the analytical strip yield model (SYM) from [9] for a center-cracked (infinite) plate with crack length 2a under mode I loading was extended to thermo-cyclic loading by accounting for the temperature dependent elastic and plastic material properties. However, solely plane stress conditions were investigated.…”

“…In contrast to isothermal loadings increasing mean stresses do not generally lead to shorter fatigue lives. Hence, it was concluded in [5] that the interaction between the temperature dependent mechanical properties and the history dependent mean stress evolution under thermomechanical fatigue loading has not been fully understood yet.…”

“…In a recent paper [5] published by the authors, the SYM was modified to account for temperature dependent elastic and plastic material properties.…”

“…It is the aim of this paper to develop a crack opening stress equation for TMF loading, which is valid for both plane stress and plane strain. To this end, the data base of IP and OP crack opening stresses in [5] is extended by calculations with the SYM for two more load ratios under plane stress and also under plane strain. The extension of the temperature dependent SYM is presented in section 2, while the results for all loading conditions are shown in section 3.…”

Erweiterungen des Fließstreifenmodells hinsichtlich verschiedener Einflussfaktoren auf das Ermüdungsrisswachstum

“…Das Fließstreifenmodell betreffend wurde eine solche Erweiterung des Modells nach dem Wissen der Autoren in den letzten drei Jahrzehnten nicht durchgeführt . Kürzlich wurde mit dem Fließstreifenmodell der Einfluss thermomechanischer In‐Phase‐ und Out‐of‐Phase‐Beanspruchung auf das plastizitätsinduzierte Rissschließen untersucht . Wie in wurde auch hier die Temperaturabhängigkeit der Fließspannung berücksichtigt, wobei – anders als in – neben den zeitlichen keine örtlichen Temperaturgradienten in der untersuchten Geometrie vorlagen.…”