Structural strain approach to assess thermo-mechanical fatigue of thin-walled welded joints.

• Fatigue life prediction of thin-walled welded structures including dissimilar joints. • Low cycle fatigue, in-phase and out-of-phase thermo-mechanical fatigue up to 750 °C. • Recommendations with guideline character and Python script for industrial use. • Fatigue assessment based on hot spot structural strains using "7-Point-Extrapolation". • Validated with exhaust components made of 1.4509 ferritic and 1.4301 austenitic steel. Widely used stress-based methods for predicting the fatigue life of welded structures are not applicable to Low Cycle Fatigue (LCF) and Thermo-Mechanical Fatigue (TMF). Hence, exhaust gas components, which often suffer LCF or TMF cannot be designed by means of these approaches. Therefore, a structural strain approach has been developed. To assess fatigue, it uses extrapolated surface strains from finite element models and corresponding structural strain-life curves resulting from tests with thin-walled welded joints. The approach is supported by guideline-like recommendations for industrial application and can be used for fatigue life prediction of LCF and TMF up to 750 °C. [ABSTRACT FROM AUTHOR]