Кинетика процесса накопления повреждений и разрушения в зонах концентраторов при испытаниях образцов на разрыв

2021 ◽  
pp. 33-44
Author(s):  
Н.А. Махутов ◽  
И.Е. Васильев ◽  
Д.В. Чернов ◽  
В.И. Иванов ◽  
Е.В. Терентьев
Keyword(s):  
Acoustic Emission ◽  
Damage Accumulation ◽  
Welded Joint ◽  
High Energy ◽  
Uniaxial Tensile ◽  
High Energy Level ◽  
Weight Content ◽  
Emission Testing ◽  
Initiation And Propagation ◽  
Acoustic Emission Testing

The paper considers the effect of various stress concentrators on processes of damage accumulation, initiation and propagation of crack in steel (steel 3) samples during uniaxial tensile. In the middle of the samples there was a transverse welded joint or a hole with a diameter of 5 mm. The acoustic-emission testing results showed that weight content of location impulses (Wi) in the clusters of low, middle and high energy level and criteria parameters value Wi at the stages of the samples destruction have similar pattern of change despite the various types of concentrators, stress-strain material diagrams, pattern of damage accumulation, number of registered acoustic emission (AE) events and its registration activity.

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.

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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