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Title: A quantitative acoustic emission study on fracture processes in ceramics based on wavelet packet decomposition

Abstract

We base a quantitative acoustic emission (AE) study on fracture processes in alumina ceramics on wavelet packet decomposition and AE source location. According to the frequency characteristics, as well as energy and ringdown counts of AE, the fracture process is divided into four stages: crack closure, nucleation, development, and critical failure. Each of the AE signals is decomposed by a 2-level wavelet package decomposition into four different (from-low-to-high) frequency bands (AA{sub 2}, AD{sub 2}, DA{sub 2}, and DD{sub 2}). The energy eigenvalues P{sub 0}, P{sub 1}, P{sub 2}, and P{sub 3} corresponding to these four frequency bands are calculated. By analyzing changes in P{sub 0} and P{sub 3} in the four stages, we determine the inverse relationship between AE frequency and the crack source size during ceramic fracture. AE signals with regard to crack nucleation can be expressed when P{sub 0} is less than 5 and P{sub 3} more than 60; whereas AE signals with regard to dangerous crack propagation can be expressed when more than 92% of P{sub 0} is greater than 4, and more than 95% of P{sub 3} is less than 45. Geiger location algorithm is used to locate AE sources and cracks in the sample. Themore » results of this location algorithm are consistent with the positions of fractures in the sample when observed under a scanning electronic microscope; thus the locations of fractures located with Geiger's method can reflect the fracture process. The stage division by location results is in a good agreement with the division based on AE frequency characteristics. We find that both wavelet package decomposition and Geiger's AE source locations are suitable for the identification of the evolutionary process of cracks in alumina ceramics.« less

Authors:
;
Publication Date:
OSTI Identifier:
22314364
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 116; Journal Issue: 8; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALGORITHMS; ALUMINIUM OXIDES; CERAMICS; CRACK PROPAGATION; CRACKS; EIGENVALUES; EMISSION; FRACTURES; MICROSCOPES; NUCLEATION; SIGNALS

Citation Formats

Ning, J. G., Chu, L., and Ren, H. L., E-mail: huilanren@bit.edu.cn. A quantitative acoustic emission study on fracture processes in ceramics based on wavelet packet decomposition. United States: N. p., 2014. Web. doi:10.1063/1.4893723.
Ning, J. G., Chu, L., & Ren, H. L., E-mail: huilanren@bit.edu.cn. A quantitative acoustic emission study on fracture processes in ceramics based on wavelet packet decomposition. United States. https://doi.org/10.1063/1.4893723
Ning, J. G., Chu, L., and Ren, H. L., E-mail: huilanren@bit.edu.cn. Thu . "A quantitative acoustic emission study on fracture processes in ceramics based on wavelet packet decomposition". United States. https://doi.org/10.1063/1.4893723.
@article{osti_22314364,
title = {A quantitative acoustic emission study on fracture processes in ceramics based on wavelet packet decomposition},
author = {Ning, J. G. and Chu, L. and Ren, H. L., E-mail: huilanren@bit.edu.cn},
abstractNote = {We base a quantitative acoustic emission (AE) study on fracture processes in alumina ceramics on wavelet packet decomposition and AE source location. According to the frequency characteristics, as well as energy and ringdown counts of AE, the fracture process is divided into four stages: crack closure, nucleation, development, and critical failure. Each of the AE signals is decomposed by a 2-level wavelet package decomposition into four different (from-low-to-high) frequency bands (AA{sub 2}, AD{sub 2}, DA{sub 2}, and DD{sub 2}). The energy eigenvalues P{sub 0}, P{sub 1}, P{sub 2}, and P{sub 3} corresponding to these four frequency bands are calculated. By analyzing changes in P{sub 0} and P{sub 3} in the four stages, we determine the inverse relationship between AE frequency and the crack source size during ceramic fracture. AE signals with regard to crack nucleation can be expressed when P{sub 0} is less than 5 and P{sub 3} more than 60; whereas AE signals with regard to dangerous crack propagation can be expressed when more than 92% of P{sub 0} is greater than 4, and more than 95% of P{sub 3} is less than 45. Geiger location algorithm is used to locate AE sources and cracks in the sample. The results of this location algorithm are consistent with the positions of fractures in the sample when observed under a scanning electronic microscope; thus the locations of fractures located with Geiger's method can reflect the fracture process. The stage division by location results is in a good agreement with the division based on AE frequency characteristics. We find that both wavelet package decomposition and Geiger's AE source locations are suitable for the identification of the evolutionary process of cracks in alumina ceramics.},
doi = {10.1063/1.4893723},
url = {https://www.osti.gov/biblio/22314364}, journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 8,
volume = 116,
place = {United States},
year = {2014},
month = {8}
}