Automatic Event Detection in Noisy Environment for Material Process Monitoring by Laser AE Method

3rd International Symposium on Laser Ultrasonics and Advanced Sensing

Ito, K.^1 ; Kuriki, H.^1 ; Araki, H.^2 ; Kuroda, S.^2 ; Enoki, M.^1

Department of Materials Engineering, School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan^1

High Temperature Materials Unit, National Institute for Materials Science, 1-2-1 Sengen, Ibaraki 305-0047 Tsukuba, Japan^2

关键词: Frequency domains;    High-temperature environment;    Multiple threshold;    Noise reduction filters;    Noisy environment;    Non-destructive evaluation methods;    Physical phenomena;    Plasma spray deposition;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/520/1/012014/pdf
DOI  :  10.1088/1742-6596/520/1/012014

来源: IOP

【 摘 要 】

Laser acoustic emission (AE) method is a unique in-situ and non-contact nondestructive evaluation (NDE) method. It has a capability to detect signals generated from crack generation and propagation, friction and other physical phenomena in materials even in high temperature environment. However, laser AE system has lower signal-to-noise ratio compared to the conventional AE system using PZT sensors, so it is difficult to apply this method in noisy environment. A novel AE measurement system to detect events in such difficult environments was developed. This system could continuously record all AE waveforms and enable unrestricted post-analyses. Noise reduction filters in frequency domain coupling with a new AE event extraction using multiple threshold values showed a good potential for AE signal processing. This system was successfully applied for crack monitoring of plasma spray deposition process of ceramic coating.