PSI - Issue 66

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2025) 000–000

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ScienceDirect

Procedia Structural Integrity 66 (2024) 102–107

8th International Conference on Crack Paths Prediction of the crack propagation direction in missions with time

varying multi-axial loading Guido Dhondt a *, Wolfram Nöhring a a MTU Aero Engines AG, Dachauer Strasse 665, 80995 Munich, Germany

Abstract The prediction of crack propagation due to arbitrary mixed-mode mission profiles is still open to debate. One of the main difficulties is how to predict the mission crack deflection angle reliably. Common criteria are the dominant step criterion and the dominant cycle criterion. In the dominant step criterion the mission propagation angle is assumed to be the one of the loading step with highest equivalent K-value and/or crack propagation rate in the mission. In the dominant cycle criterion, alternatively, a maximum and minimum loading step are identified, the difference of which defines the crack propagation angle. Extensive tension-torsion and cruciform specimen tests have revealed, that the dominant step criterion should be taken for missions purely in the tensile range, whereas the dominant cycle criterion should be used for all other types of missions. © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of CP 2024 Organizers Keywords: crack propagation; mission; deflection angle; mixed-mode; multi-axial loading; 1. Introduction Over the last decades a lot of research has concentrated on the prediction of the crack propagation direction due to mixed-mode. Several criteria have been developed and by now the deflection of the crack due to just one loading step © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of CP 2024 Organizers

* Corresponding author.. E-mail address: guido.dhondt@mtu.de

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of CP 2024 Organizers

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of CP 2024 Organizers 10.1016/j.prostr.2024.11.059