Online monitoring of pre-crack initiation in carbon fiber-reinforced thermoplastic composites by an ultrasonic cutting tool using high-speed optical imaging and infrared thermography.

Autor: Ragupathi B; Walter-and-Ingeborg-Herrmann-Chair for Power Ultrasonics and Engineering of Functional Materials (EFM), Department of Sustainable Systems Engineering (INATECH), University of Freiburg, 79110 Freiburg i. Br., Germany. Electronic address: balaji.ragupathi@inatech.uni-freiburg.de., Jakkula P; Gips-Schuele Chair for Sustainable Systems Engineering (SSE), Department of Sustainable Systems Engineering (INATECH), University of Freiburg, 79110 Freiburg i. Br., Germany., Rienks M; Walter-and-Ingeborg-Herrmann-Chair for Power Ultrasonics and Engineering of Functional Materials (EFM), Department of Sustainable Systems Engineering (INATECH), University of Freiburg, 79110 Freiburg i. Br., Germany., Balle F; Walter-and-Ingeborg-Herrmann-Chair for Power Ultrasonics and Engineering of Functional Materials (EFM), Department of Sustainable Systems Engineering (INATECH), University of Freiburg, 79110 Freiburg i. Br., Germany; Freiburg Materials Research Center FMF, 79104 Freiburg i. Br., Germany; Fraunhofer-Institute for High-Speed Dynamics, Ernst Mach Institute (EMI), 79104 Freiburg i. Br., Germany. Electronic address: frank.balle@inatech.uni-freiburg.de.
Jazyk: angličtina
Zdroj: Ultrasonics [Ultrasonics] 2024 Sep; Vol. 143, pp. 107411. Date of Electronic Publication: 2024 Jul 22.
DOI: 10.1016/j.ultras.2024.107411
Abstrakt: The ultrasonic-assisted manufacturing process is a promising machining approach for composite materials as it exerts less force, making it ideal for the aerospace and automotive sectors. This work reports about the pre-crack initiation in carbon fiber reinforced (CF)/ poly-ether-ether-ketone (PEEK) composite under ultrasonic frequency at room temperature. An iron-based cutting tool matching the system's resonance frequency (20 kHz) was used to perform the ultrasonic pre-cracking. In this novel work, the pre-cracking of CF-PEEK is considered as the initial step for a complete fiber layer separation, which holds the key for circularity options in high-performance aerospace composites. State-of-the-art high-speed camera and infrared thermography were combined to monitor the crack initiation and propagation. By online monitoring, the different stages involved in the pre-cracking process, its temperature evolution, and consequently the dissipated energy during pre-cracking under ultrasonic frequency were evaluated. The results showed that oscillation amplitude had a significant influence on the determined pre-crack depth and measured global temperature and energy compared to cutting force. The measured global temperature data indicates that pre-cracking occurred in the solid state with a temperature well below the glass-transition temperature of PEEK. However, the local temperature at the contact between the sample and sonotrode could have been much higher during ultrasonic cutting which needed further investigation. The computed global dissipated energy and temperature were only reliable at the pre-crack initiation site due to the limitation in the infrared thermography system.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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