PSI - Issue 65

ScienceDirect Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2024) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2024) 000–000 Available online at www.sciencedirect.com

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Procedia Structural Integrity 65 (2024) 275–281

The 17th International Conference on MECHANICS, RESOURCE AND DIAGNOSTICS OF MATERIALS AND STRUCTURES (MRDMS 2023) Infrared thermography applied to accelerated evaluation of the fatigue strength of structural elements made of composites D.G. Solomonov a, * and M.Sh. Nikhamkin a a Perm National Research Polytecnic University, 29 Komsomolsky Ave., Perm, 614990, Russia When designing structures made of composite materials, it is necessary to ensure their fatigue strength. This requires experimental data on fatigue resistance characteristics. The standard approach to determining these characteristics involves lengthy and expensive experimental work. In the case of composite materials, it is necessary to carry out fatigue tests of expensive full-scale structures or standard elements. This paper proposes an accelerated method of fatigue testing based on infrared thermography. It is based on the effect of self-heating of the material under cyclic loads exceeding the fatigue limit. In the study, this method is applied to a full-scale structural element, namely a shell made of laminated carbon fiber with a flange. A sample cut from the shell is subjected to block cyclic loading on a vibration stand. Self-heating is recorded during loading by means of an infrared camera. The obtained fatigue limit estimates are consistent with the results of standard tests. © 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 MRDMS 2023 organizers Keywords: structural element, fatigue test, fatigue limit, infrared thermography, carbon fiber The 17th International Conference on MECHANICS, RESOURCE AND DIAGNOSTICS OF MATERIALS AND STRUCTURES (MRDMS 2023) Infrared thermography applied to accelerated evaluation of the fatigue strength of structural elements made of composites D.G. Solomonov a, * and M.Sh. Nikhamkin a a Perm National Research Polytecnic University, 29 Komsomolsky Ave., Perm, 614990, Russia Abstract When designing structures made of composite materials, it is necessary to ensure their fatigue strength. This requires experimental data on fatigue resistance characteristics. The standard approach to determining these characteristics involves lengthy and expensive experimental work. In the case of composite materials, it is necessary to carry out fatigue tests of expensive full-scale structures or standard elements. This paper proposes an accelerated method of fatigue testing based on infrared thermography. It is based on the effect of self-heating of the material under cyclic loads exceeding the fatigue limit. In the study, this method is applied to a full-scale structural element, namely a shell made of laminated carbon fiber with a flange. A sample cut from the shell is subjected to block cyclic loading on a vibration stand. Self-heating is recorded during loading by means of an infrared camera. The obtained fatigue limit estimates are consistent with the results of standard tests. © 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 MRDMS 2023 organizers Keywords: structural element, fatigue test, fatigue limit, infrared thermography, carbon fiber Advances in the development of polymer composite materials have made it possible to use them in highly loaded critical structural elements. Many of them work under vibration conditions and experience the effects of variable loads as texted by Kelly (2008). Ensuring fatigue strength is one of the most important tasks that must be solved in such cases. It is the usual practice to conduct standard fatigue tests in order to obtain fatigue curves (S–N curves) and © 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 MRDMS 2023 organizers Abstract 1. Introduction Advances in the development of polymer composite materials have made it possible to use them in highly loaded critical structural elements. Many of them work under vibration conditions and experience the effects of variable loads as texted by Kelly (2008). Ensuring fatigue strength is one of the most important tasks that must be solved in such cases. It is the usual practice to conduct standard fatigue tests in order to obtain fatigue curves (S–N curves) and 1. Introduction

* Corresponding author. Tel.: +7-912-889-8400. E-mail address: solomonov1198@yandex.ru * Corresponding author. Tel.: +7-912-889-8400. E-mail address: solomonov1198@yandex.ru

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 MRDMS 2023 organizers 10.1016/j.prostr.2024.11.041 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 MRDMS 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 MRDMS 2023 organizers