PSI - Issue 43

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

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 43 (2023) 41–46

© 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 the responsibility of MSMF10 organizers. Abstract Bolted joints are one of the most used joining technologies in mechanical engineering. Regarding a long lifetime of the joint it is essential to prevent a fatigue failure of the bolt and a fatigue crack initiation near the borehole. In the contact zone between the sheet and the bolt head respectively nut, a multiaxial stress situation arises due to the preload of the bolt and the stresses due to the loading of the machinery. The presented research observes the correlation between the preload and load cycles to fatigue crack initiation. Therefore, a specific test setup was developed and used for a comprehensive test series with a metric bolt of diameter 22 mm and a plate made of steel S355MC (1.0976). The results show significant disparities dependent on the preload. For low preloads the fatigue cracks arise directly at the borehole and after less than 100,000 cycles. For high preloads the cracks arise in the contact zone between the nut and the sheet material. Additionally, the number of load cycles to failure increases with the preload. The stress state as well as the contact stresses were investigated by a finite element analysis. The numerical results were used for a multiaxial fatigue and contact analysis. © 20 23 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under the responsibility of MSMF10 organizers. 10th International Conference on Materials Structure and Micromechanics of Fracture Multiaxial fatigue crack initiation in bolted sheet material Robert Szlosarek a * , Matthias Kröger a a Institute for Machine Elements, Design and Manufacturing, Agricolastraße 1, 09599 Freiberg, Germany Abstract Bolted joint are one of the most used joining technologies in mechanical engineering. Regarding a l ng lif time of the joint it is essential to pr vent a fatigue failur of the bolt and a fatigue crack initiation near the borehole. In the contact zone between the sheet and the bolt head respectively nut, a multiaxial stress situ tion arises due to the preload of th bolt and the stresses due to the loading of the machinery. Th pres nted r earch observes the correlation between the preload and load cycles to fatigue crack initiation. Therefore, specific test setup was developed and used for a comprehensive test series with a metric b lt of diameter 22 mm and a plate made of steel S355MC (1.0976). T results show significant disparities dependent on the l . For low preloads the fatigue cracks arise directly at the bore ole and after less than 100,000 cycles. F r high preloads the cracks a ise in the contact z ne between the nut and th sheet materi l. Additionally, the number of load cycles to failure increases with the preload. The stres state as well s the contact stresses were investigated by a finite element analysis. The numerical results were used for a multiaxial fatigue and contact analysis. © 20 23 The Authors. Published by Elsevier B.V. This is an ope access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under the responsibility of MSMF10 organizers. 10th International Conference on Materials Structure and Micromechanics of Fracture Multiaxial fatigue crack initiation in bolted sheet material Robert Szlosarek a * , Matthias Kröger a a Institute for Machine Elements, Design and Manufacturing, Agricolastraße 1, 09599 Freiberg, Germany

Keywords: bolted joint; borehole, preload, multiaxial, fretting Keywords: bolted joint; borehole, preload, multiaxial, fretting

Nomenclature E Nomenclature E

Young’s modulus Young’s modulus load ratio load ratio Poison’s ratio Poison’s ratio

R R ν ν

* Corresponding author. Tel.: +49 3731 393653; fax: +49 3731 393658. E-mail address: robert.szlosarek@imkf.tu-freiberg.de * Correspon ing autho . Tel.: +49 3731 393653; fax: +49 3731 393658. E-mail address: robert.szlosarek@imkf.tu-freiberg.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 the responsibility of MSMF10 organizers. 2452-3216 © 2023 The Authors. Published by Elsevier B.V. This is an ope access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under the responsibility of MSMF10 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 the responsibility of MSMF10 organizers. 10.1016/j.prostr.2022.12.232