Cluster analysis of acoustic emission data to investigate the damage evolution in modified scarf joint under bi-axial loading

To explore the mechanical properties and damage evolution characteristics of carbonaceous shale with different confining pressures and water-bearing conditions, triaxial compression tests accompanied by simultaneous acoustic emission (AE) monitoring were conducted on carbonaceous shale rock specimens. The AE characteristics of carbonaceous shale were investigated, a damage assessment method based on Shannon entropy of AE was further proposed. The results suggest that the mechanical properties of carbonaceous shale intensify with increasing confining pressure and degrade with increasing water content. Moisture in rocks does not only weaken the cohesion but also reduce the internal friction angle of carbonaceous shale. It is observed that AE activities mainly occur in the post-peak stage and the strong AE activities of saturated carbonaceous shale specimens appear at a lower normalized stress level than that of natural-state specimens. The maximum AE counts and AE energy increase with water content while decrease with confining pressure. Both confining pressure and water content induce changes in the proportions of AE dominant frequency bands, but the changes caused by confining pressure are more significant than those caused by water content. The results also indicate that AE entropy can serve as an applicable index for rock damage assessment. The damage evolution process of carbonaceous shale can be divided into two main stages, including the stable damage development stage and the damage acceleration stage. The damage variable increases slowly accompanied by a few AE activities at the first stage, which is followed by a rapid growth along with intense acoustic emission activities at the damage acceleration stage. Moreover, there is a sharp rise in the damage evolution curve for the natural-state specimen at the damage acceleration stage, while the damage variable develops slowly for the saturated-state specimen.

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Diagnosis of damage evolution process for asphalt mixtures using pattern recognition with acoustic emission signals

Construction and Building Materials ◽

10.1016/j.conbuildmat.2021.122536 ◽

2021 ◽

Vol 280 ◽

pp. 122536

Author(s):

Xin Qiu ◽

Jingxian Xu ◽

Wenyi Xu ◽

Qing Yang ◽

Feng Wang ◽

...

Keyword(s):

Pattern Recognition ◽

Acoustic Emission ◽

Damage Evolution ◽

Asphalt Mixtures ◽

Evolution Process

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Shear test on damage evolution of brick masonry based on acoustic emission technique

Construction and Building Materials ◽

10.1016/j.conbuildmat.2020.121782 ◽

2021 ◽

pp. 121782

Author(s):

Shengli Li ◽

Yanqi Wu ◽

Wenxia Li ◽

Panjie Li

Keyword(s):

Acoustic Emission ◽

Damage Evolution ◽

Shear Test ◽

Brick Masonry ◽

Acoustic Emission Technique

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Discriminant analysis of acoustic emission data to determine failure modes of lead frame bonds in film integrated circuits

NDT International ◽

10.1016/0308-9126(82)90022-0 ◽

1982 ◽

Vol 15 (4) ◽

pp. 185-195 ◽

Cited By ~ 2

Author(s):

M.C. Jon ◽

G.W. Sturm

Keyword(s):

Acoustic Emission ◽

Discriminant Analysis ◽

Integrated Circuits ◽

Failure Modes ◽

Lead Frame ◽

Emission Data

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Damage evolution analysis in mortar, during compressive loading using acoustic emission and X-ray tomography: Effects of the sand/cement ratio

Cement and Concrete Research ◽

10.1016/j.cemconres.2007.02.008 ◽

2007 ◽

Vol 37 (5) ◽

pp. 703-713 ◽

Cited By ~ 70

Author(s):

H. Elaqra ◽

N. Godin ◽

G. Peix ◽

M. R'Mili ◽

G. Fantozzi

Keyword(s):

Acoustic Emission ◽

Damage Evolution ◽

Compressive Loading ◽

Cement Ratio ◽

X Ray ◽

Evolution Analysis

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Acoustic emission waveforms for damage monitoring in composite materials: Shifting in spectral density, entropy and wavelet packet transform

Structural Health Monitoring ◽

10.1177/14759217211044692 ◽

2021 ◽

pp. 147592172110446

Author(s):

Claudia Barile ◽

Caterina Casavola ◽

Giovanni Pappalettera ◽

Vimalathithan Paramsamy Kannan

Keyword(s):

Acoustic Emission ◽

Spectral Density ◽

Flicker Noise ◽

Wavelet Packet ◽

Research Work ◽

Wavelet Packet Transform ◽

Spectral Energy ◽

Emission Data ◽

Cfrp Composites ◽

Damage Process

Signal-based acoustic emission data are analysed in this research work for identifying the damage modes in carbon fibre–reinforced plastic (CFRP) composites. The research work is divided into three parts: analysis of the shifting in the spectral density of acoustic waveforms, use of waveform entropy for selecting the best wavelet and implementation of wavelet packet transform (WPT) for identifying the damage process. The first two methodologies introduced in this research work are novel. Shifting in the spectral density is introduced in analogous to ‘flicker noise’ which is popular in the field of waveform processing. The entropy-based wavelet selection is refined by using quadratic Renyi’s entropy and comparing the spectral energy of the dominating frequency band of the acoustic waveforms. Based on the method, ‘dmey’ wavelet is selected for analysing the waveforms using WPT. The slope values of the shifting in spectral density coincide with the results obtained from WPT in characterising the damage modes. The methodologies introduced in this research work are promising. They serve the purpose of identifying the damage process effectively in the CFRP composites.

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