The measurement of fiber strength parameters in fragmentation tests by using acoustic emission

Clough, R. B.; McDonough, Walter G.

doi:10.1016/s0266-3538(96)00076-0

Cited by 23 publications

(9 citation statements)

References 14 publications

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“…Yet, the test time can be significantly reduced. In the acoustic emission technique by Clough and McDonough (1996), the amount of time required for each test is a minute or less.…”

Section: Discussionmentioning

confidence: 99%

“…In addition, the longer test time can cause creep in the specimens, generating error in the data. The acoustic emission technique overcomes the problems of visibility and creep since data is acoustically collected at the precise stress/strain level and not after each stress/strain increment, as in the optical technique (Clough and McDonough 1996). The equipment used for detecting acoustic emission, however, must be very sensitive and capable of filtering out background noise.…”

Section: Discussionmentioning

confidence: 99%

“…This step can induce creep in the specimen, as shown by Clough and McDonough (1996). Third, it is sometimes very difficult to identify the small gaps between fiber fragments, which are usually <1 jim.…”

Section: Acoustic Emission Data Acquisitionmentioning

confidence: 99%

See 2 more Smart Citations

A Survey of Current High-Performance Carbon Fiber Characterization Methods

Nguyen¹,

Ghiorse²,

Mulkern³

2000

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This report reviews various test techniques published in the literature for evaluating carbon fiber via the single-filament tensile test, the dry bundle test, the resin-impregnated strand test, and the single-fiber fragmentation test (optical microscopy and acoustic emission). Experimental procedures, data analysis, and statistical tensile strength theory are also described. Each technique is followed by a discussion of the advantages and limitations. Furthermore, a materials property database has been developed that includes mechanical properties for several commercially available carbon fibers.n Acknowledgments

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“…Yet, the test time can be significantly reduced. In the acoustic emission technique by Clough and McDonough (1996), the amount of time required for each test is a minute or less.…”

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

A Survey of Current High-Performance Carbon Fiber Characterization Methods

Nguyen¹,

Ghiorse²,

Mulkern³

2000

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“…AE signal is a transient wave resulting from real-time and continuous monitoring of micro failures (e.g. matrix cracking, debonding of matrix from fiber and fiber failure) during delamination phenomenon [3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Analysis of the damage mechanisms in mixed-mode delamination of laminated composites using acoustic emission data clustering

Fotouhi

Sadeghi

Jalalvand

et al. 2016

Journal of Thermoplastic Composite Materials

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In this study, acoustic emission (AE) technique is used to investigate different time-to-failure mechanisms of delamination in glass/epoxy composite laminates. Woven and unidirectional layups were subjected to the double cantilever beam, end notch flexure, and mixed-mode bending tests and the generated AE signals were captured. Discrimination of the AE events, caused by different types of the damage mechanisms, was performed using wavelet packet transform (WPT) and fuzzy clustering method (FCM) associated with a principal component analysis (PCA). The FCM and WPT analyses identified three dominant damage mechanisms. Furthermore, different interface layups and different GII/GT modal ratio values (ratio of mode II strain energy release rate per total strain energy release rate) indicated different time-to-failure mechanisms incidence. Additionally, the damaged mechanisms were observed using scanning electron microscopic (SEM) analysis. The results showed that the dominant damage mechanisms in all the specimens are matrix cracking and fiber–matrix debonding. Besides, some fiber breakage appeared during the tests, and the percentage of this damage mechanism in the unidirectional specimens and mode I condition was higher than those in the woven specimens and mode II. SEM observations were also in good agreement with the obtained results. It was found that the presented methods can be utilized to improve the characterization and discrimination of damage mechanisms in the actual occurring modes of delamination in composite structures.

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“…Acoustic emission (AE) technique which is well known for its high sensitivity and capability of real-time monitoring [13] is later used to assist such experiments in identifying and locating local cracks or failures in composites. However, due to the difficulties in signal analysis and high cost associated with the AE technique, Clough [14] proposed to use the number of the fiber breaks as a function of stress or strain. Similar idea was also employed by Minko [15] who demonstrated the Clough's suggestion to determine the global debonding stress (GDS) in spherically shaped micron-sized particle reinforced polymer composites.…”

Section: Introductionmentioning

confidence: 99%

Determination of local debonding stress and investigation of its effect on mechanical properties of glass short fiber reinforced polycarbonate composites

2012

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Thermoplastic polymers are often reinforced by adding short fibers to improve mechanical properties including Young's modulus and tensile strength of the polymers. In many engineering applications, energy absorbing characteristics in such particulate polymers is known to be a very important property to be considered in composite designs, and meanwhile debonding at the interface between fiber and matrix in the composites may affect the energy absorption properties. Here, the focus of this study is to employ a semi-empirical approach to determine the debonding stress and investigate the effect of the debonding stress on energy absorbing properties of short glass fiber reinforced polycarbonate composites. Glass short fiber reinforced polycarbonate composites are fabricated via a solution mixing technique. Tensile testing and acoustic emission measurement are simultaneously performed for the polycarbonate composites. The test results including toughness are compared for the composites over neat polycarbonate. Also the local debonding stress in the vicinity of each glass fiber in composites is estimated by combining modeling and experiments. A finite element model is developed to determine local debonding stress at the interface between the fiber and matrix. The local debonding stress appears to considerably affect the toughness of the composites.

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The measurement of fiber strength parameters in fragmentation tests by using acoustic emission

Cited by 23 publications

References 14 publications

A Survey of Current High-Performance Carbon Fiber Characterization Methods

A Survey of Current High-Performance Carbon Fiber Characterization Methods

Analysis of the damage mechanisms in mixed-mode delamination of laminated composites using acoustic emission data clustering

Determination of local debonding stress and investigation of its effect on mechanical properties of glass short fiber reinforced polycarbonate composites

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