PSI - Issue 57

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2022) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000 ScienceDirect

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ScienceDirect

Procedia Structural Integrity 57 (2024) 649–657

© 2024 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 the scientific committee of the Fatigue Design 2023 organizers © 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 the scientific committee of the Fatigue Design 2023 organizers Abstract The study investigates the mechanical properties and fatigue behavior of steering knuckles used on commercial vehicles. The steering knuckle is made of hot forged bainitic steel (18MnCrMoV6-4-8), which is known to demonstrate high levels of fatigue strength, toughness, and hardness. The local strain concept was adopted to assess the durability of the steering knuckle based on the stabilized cyclic material behavior. For this purpose, experimental investigations have been conducted on both the steering knuckle as well as fatigue specimens under constant and variable amplitude loadings. The fatigue specimens were removed from the area next to the crack initiation location, to represent the microstructure in the critical area of the component. Fatigue life estimations were performed under different load ratios using the FKM guideline nonlinear, employing damage parameters PRAM and PRAJ. The assessment enables a fatigue strength assessment for the steering knuckle by considering the local non-linear material behavior. The estimations of the material's fatigue lifetime using the FKM guideline nonlinear approach were unsatisfactory. © 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 the scientific committee of the Fatigue Design 2023 organizers Fatigue Design 2023 (FatDes 2023) Fatigue Analysis of Steering Knuckles Using the Local Strain Approach Ahmad Qaralleh a,* , Andreas Maciolek a , Jan Weichert b , Benjamin Möller a , Tobias Melza, b a Fraunhofer LBF, Institute for Structural Durability and System Reliability, Bartningstraße 47, 64289 Darmstadt, Germany b Technical University of Darmstadt, Research Group System Reliability, Adaptive Structures, and Machine Acoustics SAM, Otto-Berndt-Straße 2, 64287 Darmstadt, Germany Abstract The study investigates the mechanical properties and fatigue behavior of steering knuckles used on commercial vehicles. The steering knuckle is made of hot forged bainitic steel (18MnCrMoV6-4-8), which is known to demonstrate high levels of fatigue strength, toughness, and hardness. The local strain concept was adopted to assess the durability of the steering knuckle based on the stabilized cyclic material behavior. For this purpose, experimental investigations have been conducted on both the steering knuckle as well as fatigue specimens under constant and variable amplitude loadings. The fatigue specimens were removed from the area next to the crack initiation location, to represent the microstructure in the critical area of the component. Fatigue life estimations were performed under different load ratios using the FKM guideline nonlinear, employing damage parameters PRAM and PRAJ. The assessment enables a fatigue strength assessment for the steering knuckle by considering the local non-linear material behavior. The estimations of the material's fatigue lifetime using the FKM guideline nonlinear approach were unsatisfactory. Fatigue Design 2023 (FatDes 2023) Fatigue Analysis of Steering Knuckles Using the Local Strain Approach Ahmad Qaralleh a,* , Andreas Maciolek a , Jan Weichert b , Benjamin Möller a , Tobias Melza, b a Fraunhofer LBF, Institute for Structural Durability and System Reliability, Bartningstraße 47, 64289 Darmstadt, Germany b Technical University of Darmstadt, Research Group System Reliability, Adaptive Structures, and Machine Acoustics SAM, Otto-Berndt-Straße 2, 64287 Darmstadt, Germany Keywords: Fatigue Life; Bainitic steel; Local Strain Concept; Cyclic material behavior; Steering knuckle; FKM guideline nonlinear.

Keywords: Fatigue Life; Bainitic steel; Local Strain Concept; Cyclic material behavior; Steering knuckle; FKM guideline nonlinear.

* Corresponding author. Tel.: +49 6151 705-640 E-mail address: ahmad.qaralleh@lbf.fraunhofer.de * Corresponding author. Tel.: +49 6151 705-640 E-mail address: ahmad.qaralleh@lbf.fraunhofer.de

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 the scientific committee of the Fatigue Design 2023 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 the scientific committee of the Fatigue Design 2023 organizers

2452-3216 © 2024 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 the scientific committee of the Fatigue Design 2023 organizers 10.1016/j.prostr.2024.03.072