Proper b-value Estimation Method in Rock Acoustic Emission Testing

The failure behavior of composites under ultraviolet (UV) irradiation was investigated by acoustic emission (AE) testing and Ib-value analysis. AE signals were acquired from woven glass fiber/epoxy specimens tested under tensile load. Cracks initiated earlier in UV-irradiated specimens, with a higher crack growth rate in comparison to the pristine specimen. In the UV-degraded specimen, a serrated fracture surface appeared due to surface hardening and damaged interfaces. All specimens displayed a linearly decreasing trend in Ib-values with an increasing irradiation time, reaching the same value at final failure even when the starting values were different.

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Study of the Metal Crack Propagation by Acoustic Emission Testing

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.105-107.2179 ◽

2011 ◽

Vol 105-107 ◽

pp. 2179-2182

Author(s):

Wei Min Zhang ◽

Shu Xuan Liu ◽

Yong Qiu ◽

Cheng Feng Chen

Keyword(s):

Acoustic Emission ◽

Crack Propagation ◽

Acquisition System ◽

Signal Acquisition ◽

Sensor Signal ◽

Acoustic Emission Sensor ◽

Axial Tension ◽

Emission Testing ◽

Acoustic Emission Testing ◽

Signal Operating

Crack propagation is the main reason which leads to the invalidity of the metal components. A set of detecting equipment based on the acoustic emission method was designed, and it was mainly composed of acoustic emission sensor, signal operating circuits and signal acquisition system. Specimens of 16MnR material were manufactured and the static axial tension test of them was carried on. Acoustic emission signals from the specimen were detected by acoustic emission equipment by using piezoelectric ceramic sensor. Signal datum were acquired and operated by the acquisition system, as well as the acquisition program written for it. The final results has demonstrated that acoustic emission equipment designed for the test performed well in acquiring the signals induced by the metal crack propagation.

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Acoustic Emission Testing of Concrete Frame during Pseudo Dynamic Loading

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.13-14.195 ◽

2006 ◽

Vol 13-14 ◽

pp. 195-200

Author(s):

Athanasios Anastasopoulus ◽

S. Bousias ◽

A. Tsimogiannis ◽

T. Toutountzakis

Keyword(s):

Acoustic Emission ◽

Dynamic Testing ◽

Frame Structure ◽

Scale Model ◽

Reinforced Concrete Frame ◽

Energy Rate ◽

Concrete Frame ◽

Emission Testing ◽

Real Size ◽

Acoustic Emission Testing

Acoustic Emission (AE) monitoring was performed during Pseudo-Dynamic Testing of a torsionally unbalanced, two-storey, one-by-one bay reinforced concrete frame structure. The structure represented a 0.7-scale model of a real-size frame structure designed and detailed according to the standards prevailing in Greece in 60's, without engineered earthquake resistance. Real time monitoring of AE activity versus the complex applied load resulted in semi quantitative damage characterization as well as comparative evaluation of the damage evolution of the different size columns. Evolution of the AE energy rate per channel, as revealed from zonal location, and the energy rate of linearly located sources enabled the identification of damage areas and the forecast of crack locations before cracks were visible with naked eye. In addition to that, the results of post processing evaluation allowed for the verification of the witnessed damaged areas and formed the basis for quantitative assessment of damage criticality.

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On the Reproducibility of Transducer Coupling for Acoustic Emission Testing

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.13-14.117 ◽

2006 ◽

Vol 13-14 ◽

pp. 117-124 ◽

Cited By ~ 2

Author(s):

James J. Hensman ◽

C.V. Cristodaro ◽

Gareth Pierce ◽

Keith Worden

Keyword(s):

Acoustic Emission ◽

Test Results ◽

Coupling Condition ◽

Waveform Data ◽

Three Point Bending ◽

Emission Testing ◽

Acoustic Emission Testing ◽

Acoustic Emission Test ◽

Point Bend ◽

Ultrasonic Propagation

An acoustic emission test was simulated using a three point bend specimen and an artificial AE source. Waveform data was recorded as the sample was cyclically loaded in three point bending, and the cross correlation coefficient of the waveforms was used to measure the repeatability of the test. Results were twofold: the stress state of a specimen affects the ultrasonic propagation therein; and the coupling condition of a transducer may not remain constant during a test.

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