PSI - Issue 46

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2021) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 46 (2023) 3–9

© 2023 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 ICSID 2021 Organizers Numerical investigations by means of elastic–plastic finite element analyses were carried out to estimate the local stress conditions acting in the blade root. The local stresses and strains were post-processed using the critical plane approach and advanced fatigue damage parameters. Finally, the estimated numerical lifetimes were compared with the experimental results of the component tests on original-sized end stage blades. © 2021 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 ICSID 2021 Organizers Keywords: component test; end stage blades; multiaxial fatigue; finite elemente analysis; fatigue assessment; lifetime evaluation 1. Introduction The increased use of regenerative energies results in modified requirements for fossil power plants regarding extended partial load efficiency, accelerated load changes, and the climate policy-based desire for an increase in 5th International Conference on Structural Integrity and Durability Component tests and numerical investigations to determine the lifetime and failure behavior of end stage blades L. Frank a, *, S. Weihe a a Materials Testing Institue (MPA) University of Stuttgart, Pfaffenwaldring 32, 70569 Stuttgart, Germany Abstract The paper focuses on experimental and numerical fatigue assessment procedures to evaluate the influence of multiaxial stress state caused by high centrifugal forces superimposed with bending loads due to blade vibrations on the lifetime of end stage blades from steam turbines. The experimental investigations on original-sized end stage blades were carried out on a test rig especially developed for high forces and multicomponent force application based on detailed numerical simulations by the MPA University of Stuttgart. During the fractographic post-examinations of the tested blades using magnetic particle inspection, light and scanning electron microscopes, two competing damage mechanisms were identified, which occurred at different locations.

* Corresponding author. Tel.: +49 (0) 711-685-63954 E-mail address: lukas.frank@mpa.uni-stuttgart.de

2452-3216 © 2021 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 ICSID 2021 Organizers

2452-3216 © 2023 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 ICSID 2021 Organizers 10.1016/j.prostr.2023.06.002