PSI - Issue 42

Florian Garnadt et al. / Procedia Structural Integrity 42 (2022) 1113–1120 F. Garnadt et al. / Structural Integrity Procedia 00 (2019) 000–000

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The factor depends slightly on the loading level, but significantly on the presence of dwell times. The paper shows that this is caused by an impact of dwell times on crack closure and therefore the cyclic e ff ective J -Integral. A separation of crack tip loading for the loading and unloading part of the cycle allows for consideration of this impact. Furthermore, the results are validated by experimental measurement of ECG and investigations of a cruciform specimen with a center borehole as a di ff erent notch geometry and loading condition. Finally, an application example of a borehole in a thick-walled casing is presented to demonstrate the usefulness of the modelling approach. The lifetime beneficial e ff ect of notch support can be considered in assessment procedures by shifting the fatigue life curve for the structures with notch using the outlined computational scheme.

Acknowledgements

This research was financially supported by the Research Association for the Iron and Metal Processing Industry eV (AVIF), Germany. The support of the Research Association for Combustion Engines eV (FVV), the working group “W 10 High-temperature Behavior” and the project chairman Dipl.-Ing. Henning Almstedt (Siemens Energy) is gratefully acknowledged.

References

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