Modal Acoustic Emission of Damage Accummulation in Woven SiC/SiC at Elevated Temperatures

Morscher, Gregory N.

doi:10.1007/978-1-4615-4791-4_52

Cited by 7 publications

(3 citation statements)

References 11 publications

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“…22. It is important to note that the location of the events could be determined from the speed of sound of the damaged material, which was determined experimentally, and the difference in times of arrival of the wave forms corresponding to the same event on the two AE sensors.…”

Section: Methodsmentioning

confidence: 99%

“…The location was determined by the difference in times of arrival of the initial extensional wave portion of the AE wave form based on the accumulated damage (reduction in elastic modulus). 22,23 The data were sorted so that only events which occurred in the Ϯ30 mm region of the sample were analyzed. The data were also sorted according to the energy of each AE event.…”

Section: (2) Acoustic Emission Data and Matrix Crackingmentioning

confidence: 99%

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Intermediate‐Temperature Stress Rupture of a Woven Hi‐Nicalon, BN‐Interphase, SiC‐Matrix Composite in Air

Morscher

Hurst

Brewer

2000

Journal of the American Ceramic Society

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108

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Woven Hi-Nicalon TM -reinforced melt-infiltrated SiC-matrix composites were tested under tensile stress-rupture conditions in air at intermediate temperatures. A comprehensive examination of the damage state and the fiber properties at failure was performed. Modal acoustic emission analysis was used to monitor damage during the experiment. Extensive microscopy of the composite fracture surfaces and the individual fiber fracture surfaces was used to determine the mechanisms leading to ultimate failure. The rupture properties of these composites were significantly worse than expected compared with the fiber properties under similar conditions. This was due to the oxidation of the BN interphase. Oxidation occurred through the matrix cracks that intersected the surface or edge of a tensile bar. These oxidation reactions resulted in strong bonding of the fibers to one another at regions of near fiber-to-fiber contact. It was found that two regimes for rupture exist for this material: a high-stress regime where rupture occurs at a fast rate and a low-stress regime where rupture occurs at a slower rate. For the high-stress regime, the matrix damage state consisted of through-thickness cracks. The average fracture strength of fibers that were pulled out (the final fibers to break before ultimate failure) was controlled by the slow-crack-growth rupture criterion in the literature for individual Hi-Nicalon fibers. For the low-stress regime, the matrix damage state consisted of microcracks which grew during the rupture test. The average fracture strength of fibers that were pulled out in this regime was the same as the average fracture strength of individual fibers pulled out in as-produced composites tested at room temperature.

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Section: Methodsmentioning

confidence: 99%

Section: (2) Acoustic Emission Data and Matrix Crackingmentioning

confidence: 99%

Intermediate‐Temperature Stress Rupture of a Woven Hi‐Nicalon, BN‐Interphase, SiC‐Matrix Composite in Air

Morscher

Hurst

Brewer

2000

Journal of the American Ceramic Society

Self Cite

108

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“…Nozawa et al [7] studied the failure behavior of SiC composites by analyzing the cumulative AE energy. Morscher [8] showed the relation between AE and stress vs. strain curve of a SiC fiber reinforced SiC matrix composite at elevated temperatures. More recently, Alva [3] used normalized cumulative AE energy and time intervals between the acoustic events to calculate the damage variable and re-built the stress vs. strain figure for the SiC composites.…”

Section: Introductionmentioning

confidence: 99%

Online Damage Monitoring of SiC_f-SiC_m Composite Materials Using Acoustic Emission and Deep Learning

et al. 2019

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SiC f -SiC m composites are being actively developed as fuel cladding for improving accident tolerance of light water reactor fuel. Online monitoring of the degradation process in SiC f -SiC m composites is of great importance to ensure the safety of the nuclear reactor system. The degradation monitoring task can be mapped as a classification problem: given the Acoustic Emission(AE) events at a given timeslot, the model is expected to predict which one of the following three stages the material is in: elastic, matrix-driven and fiber-driven cracking. In this paper, degradation tests on SiC f -SiC m composite tubes were conducted using a bladder-based internal pressure technique with AE monitoring. We then trained a deep learning based endto-end convolutional neural network (CNN) model for online monitoring of the damage progression process of SiC f -SiC m composite tubes using the AE data as the raw input. As a comparison, we also applied Random Forest (RF) with expert-crafted audio event features to the damage stage prediction problem. Experimental results show that both RF and CNN models yield good results but on average our end-to-end CNN models outperform the RF models due to its high-level feature extraction capability. The CNN model with single events can reach an average prediction accuracy of 84.4% compared to 74% of the RF models. Combining multiple audio samples typically improves the accuracy of the models with RF accuracy reaching 82.8% and CNN accuracy reaching 86.6%.INDEX TERMS Acoustic emission (AE), convolutional neural network (CNN), deep learning, online damage monitoring, random forest (RF), SiC composites.

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Growth of Matrix Cracks During Intermediate Temperature Stress Rupture of a SiC/SiC Composite in Air

Morscher

Ceramic Engineering and Science Proceedings

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Modal Acoustic Emission of Damage Accummulation in Woven SiC/SiC at Elevated Temperatures

Cited by 7 publications

References 11 publications

Intermediate‐Temperature Stress Rupture of a Woven Hi‐Nicalon, BN‐Interphase, SiC‐Matrix Composite in Air

Intermediate‐Temperature Stress Rupture of a Woven Hi‐Nicalon, BN‐Interphase, SiC‐Matrix Composite in Air

Online Damage Monitoring of SiC_f-SiC_m Composite Materials Using Acoustic Emission and Deep Learning

Growth of Matrix Cracks During Intermediate Temperature Stress Rupture of a SiC/SiC Composite in Air

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Modal Acoustic Emission of Damage Accummulation in Woven SiC/SiC at Elevated Temperatures

Cited by 7 publications

References 11 publications

Intermediate‐Temperature Stress Rupture of a Woven Hi‐Nicalon, BN‐Interphase, SiC‐Matrix Composite in Air

Intermediate‐Temperature Stress Rupture of a Woven Hi‐Nicalon, BN‐Interphase, SiC‐Matrix Composite in Air

Online Damage Monitoring of SiCf-SiCm Composite Materials Using Acoustic Emission and Deep Learning

Growth of Matrix Cracks During Intermediate Temperature Stress Rupture of a SiC/SiC Composite in Air

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Online Damage Monitoring of SiC_f-SiC_m Composite Materials Using Acoustic Emission and Deep Learning