PSI - Issue 57

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

www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 57 (2024) 179–190

Fatigue Design 2023 (FatDes 2023) In-Situ Image-based Crack Measurement Methodology for Gear Fatigue Design 2023 (FatDes 2023) In-Situ Image-based Crack Measurement Methodology for Gear

Single Tooth Bending Fatigue Testing Haelie Egbert, Ahmet Kahraman, Isaac Hong* The Ohio State University, 201 W. 19 th Ave. Columbus, OH 43210, USA Single Tooth Bending Fatigue Testing Haelie Egbert, Ahmet Kahraman, Isaac Hong* The Ohio State University, 201 W. 19 th Ave. Columbus, OH 43210, USA

Abstract

© 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 Keywords: gears; bending fatigue; crack propogation; Gear teeth undergo cyclic forces as they travel through the mesh zone. The resultant contact and bending stresses produce fatigue damage, which can lead to failure through contact surface degradation and tooth breakage through the root fillet. The fatigue process is not instantaneous, and damage accumulates at different rates throughout the fatigue life. Many proposed diagnostics and health monitoring techniques to detect the onset of gear failure are based on changes in mechanical properties due to crack growth. Moreover, theoretical studies to predict fatigue crack growth rate rely on only a few experimental measurements for their validation with little extension to gears which typically have a gradient in material properties between a hardened case and a soft core. The focus of this study is to develop an image-based system for measuring surface crack length in gear tooth bending fatigue of a spur gear. A gear single tooth bending test methodology is utilized in conjunction with a high-speed camera setup to image the tooth during every loading cycle. An image processing technique is developed and used to compute crack length during each load cycle to obtain cyclic crack growth rate. © 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 Keywords: gears; bending fatigue; crack propogation; Gear teeth undergo cyclic forces as they travel through the mesh zone. The resultant contact and bending stresses produce fatigue damage, which can lead to failure through contact surface degradation and tooth breakage through the root fillet. The fatigue process is not instantaneous, and damage accumulates at different rates throughout the fatigue life. Many proposed diagnostics and health monitoring techniques to detect the onset of gear failure are based on changes in mechanical properties due to crack growth. Moreover, theoretical studies to predict fatigue crack growth rate rely on only a few experimental measurements for their validation with little extension to gears which typically have a gradient in material properties between a hardened case and a soft core. The focus of this study is to develop an image-based system for measuring surface crack length in gear tooth bending fatigue of a spur gear. A gear single tooth bending test methodology is utilized in conjunction with a high-speed camera setup to image the tooth during every loading cycle. An image processing technique is developed and used to compute crack length during each load cycle to obtain cyclic crack growth rate. Abstract

* Corresponding author. Tel.: +1-614-688-2930 E-mail address: hong.250@osu.edu

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 * Corresponding author. Tel.: +1-614-688-2930 E-mail address: hong.250@osu.edu

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.2024.03.021