scholarly journals Acoustic Emission Testing and Ib-Value Analysis of Ultraviolet Light-Irradiated Fiber Composites

2021 ◽  
Vol 11 (14) ◽  
pp. 6550
Author(s):  
Doyun Jung ◽  
Wonjin Na
Keyword(s):  
Acoustic Emission ◽  
Irradiation Time ◽  
Tensile Load ◽  
Failure Behavior ◽  
Value Analysis ◽  
Emission Testing ◽  
Final Failure ◽  
Acoustic Emission Testing ◽  
Woven Glass Fiber ◽  
Ae Signals

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.

Acoustic Emission Testing of a Process Reactor

2005 ◽  
Author(s):  
Simon Yuen ◽  
David Wang ◽  
Paul Benedictus
Keyword(s):  
Acoustic Emission ◽  
Slag Inclusion ◽  
Thick Wall ◽  
Operating Pressure ◽  
Weld Overlay ◽  
Emission Testing ◽  
Acoustic Emission Testing ◽  
Acoustic Emission Test ◽  
Ae Signals

An Acoustic Emission Test (AET) was performed on a hydrocarbon processing reactor to inspect for environmental cracking in 2000. The thick-wall reactor was built in 1965, fabricated from 2.25Cr-1Mo steel with Type 347 stainless steel weld overlay. Past internal inspections of the reactor using liquid penetrant had revealed cracking at internal ring supports. Such inspections were exhaustive and time consuming. The AET was performed to achieve 100% inspection coverage of the reactor and to identify suspect areas for further evaluation. The test included over-pressurization of the reactor to 10% above its operating pressure before the shutdown and the actual cooling of the reactor from 745°F to 300°F. Upon completion of the acoustic emission (AE) monitoring, significant indications were identified, most noticeably at the reactor dump nozzle and the bottom head to shell weld. Both of these were in areas that had not been inspected previously. Follow-up inspections, including external ultrasonic and internal liquid penetrant test, were performed to investigate all the areas of significant AE activities. The results showed internal cracks isolated to the weld overlay at the catalyst dump nozzle and a 12” long weld slag inclusion in the bottom head to shell weld. A methodology was developed also to evaluation criticality of AE signals during different stages of AE test.

Study of the Metal Crack Propagation by Acoustic Emission Testing

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.

Acoustic Emission Testing of Concrete Frame during Pseudo Dynamic Loading

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.

On the Reproducibility of Transducer Coupling for Acoustic Emission Testing

2006 ◽  
Vol 13-14 ◽  
pp. 117-124 ◽  
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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