PSI - Issue 68

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2025) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 68 (2025) 1319–1323

European Conference on Fracture 2024 Method for predicting crack size using amplitude change in titanium alloy under bending vibration Junji Sakamoto a, *, Naoya Tada a , Takeshi Uemori a a Okayama University, Faculty of Environmental, Life, Natural Science and Technology, 3-1-1 Tsushimanaka, Kita-ku, Okayama, 700-8530, Japan Abstract The natural frequency of a material decreases owing to the presence of cracks. Thus, when a crack initiates in a material under vibration, the amplitude of the vibration changes with the crack propagation. In this study, we investigated a method for predicting crack size using the amplitude change in a plate specimen of a titanium alloy under bending vibration. The bending displacement amplitudes were measured using high-speed camera images of the specimens. The crack sizes were measured using optical microscopy images of plastic replicas of the specimen surfaces that were obtained after interrupting tests at specified intervals. By using the relationship between the total area of the cracks and bending displacement amplitude for tests at two different vibration frequencies as well as the relationship between the vibration frequency and bending displacement amplitude for an undamaged specimen, the bending displacement amplitude at any vibration frequency can be monitored to predict the total area of the cracks. © 2025 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 ECF24 organizers Keywords: Vibration; Fatigue crack propagation; Non-destructive inspection; Titanium alloy 1. Introduction Some machines generate vibrations while performing their work, whereas others are subjected to unavoidable vibrations. When using such machines, it is important to ensure safety against vibrations. In this study, we focused on the fracture processes of materials subjected to vibrations. © 2025 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 ECF24 organizers

* Corresponding author. Tel.: +81-86-251-8031; fax: +81-86-251-8031. E-mail address: sakamoto-junji@okayama-u.ac.jp

2452-3216 © 2025 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 ECF24 organizers

2452-3216 © 2025 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 ECF24 organizers 10.1016/j.prostr.2025.06.205