PSI - Issue 46

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

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

Procedia Structural Integrity 46 (2023) 99–104

© 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 Abstract The paper presents a method to determine the S-N curve for low probability of failure e.g. 5 % using a small number of specimens from the fatigue tests and taking a standard deviation from the tensile test (distribution for the logarithm of the yield strength). Verification of the method was carried out for fatigue tests of constructive steel S355J2+C and stainless steel 1.4301. The tests were performed on a rotary bending machine. The obtained results shown that the proposed method gives lower fatigue strength for a 5 % probability of failure than the S-N curve estimated acc. ISO-12107, (2012) standard. So, the proposed method is conservative and can be used by engineers. © 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: S-N curve; high-cycle fatigue; probability of failure;normal distribution; scatter of fatigue tests; 1. Introduction Designing new parts of machines must be known fatigue strength for a design lifetime, which can be expressed by a number of cycles. For this purpose S-N curves can be used. The recommended characteristics refer to max. 5 % probability of failure PN-EN 1993-1-9, (2007), PN-EN 13749, (2011) and Hobbacher, (2008). Where humans life is dangerous by failure of machines, it is required to make fatigue tests. Fatigue tests of materials and structural elements are time-consuming and require specialized equipment and qualified personnel, which makes them expensive. For this reason, normative documents were developed to define the minimum number of samples to determine the fatigue 5th International Conference on Structural Integrity and Durability Determination of standard deviation for fatigue strength based on the tensile test Przemysław Strzelecki a* a Bydgoszcz University of Science and Technology, Faculty of Mechanical Engineering, Kaliskiego 7,85-796 Bydgoszcz, Poland Abstract The paper presents a method to determine the S-N curve for low probability of failure e.g. 5 % using a small number of specimens from the fatigue tests and taking a standard deviation from the tensile test (distribution for the logarithm of the yield strength). Verification of the method was carried out for fatigue tests of constructive steel S355J2+C and stainless steel 1.4301. The tests were performed on a rotary bending machine. The obtained results shown that the proposed method gives lower fatigue strength for a 5 % probability of failure than the S-N curve estimated acc. ISO-12107, (2012) standard. So, the proposed method is conservative and can be used by engineers. © 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: S-N curve; high-cycle fatigue; probability of failure;normal distribution; scatter of fatigue tests; 1. Introduction Designing new parts of machines must be known fatigue strength for a design lifetime, which can be expressed by a number of cycles. For this purpose S-N curves can be used. The recommended characteristics refer to max. 5 % probability of failure PN-EN 1993-1-9, (2007), PN-EN 13749, (2011) and Hobbacher, (2008). Where humans life is dangerous by failure of machines, it is required to make fatigue tests. Fatigue tests of materials and structural elements are time-consuming and require specialized equipment and qualified personnel, which makes them expensive. For this reason, normative documents were developed to define the minimum number of samples to determine the fatigue 5th International Conference on Structural Integrity and Durability Determination of standard deviation for fatigue strength based on the tensile test Przemysław Strzelecki a* a Bydgoszcz University of Science and Technology, Faculty of Mechanical Engineering, Kaliskiego 7,85-796 Bydgoszcz, Poland

* Corresponding author. Tel.: +48523408672. E-mail address: p.strzelecki@utp.edu.pl * Corresponding author. Tel.: +48523408672. E-mail address: p.strzelecki@utp.edu.pl

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 © 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.2023.06.017