Quantitative Relationship between Strain and Acoustic Emission Response in Monitoring Fatigue Damage

2013 ◽  
Vol 66 (1) ◽  
Author(s):  
M. Mohammad ◽  
S. Abdullah ◽  
N. Jamaludin ◽  
O. Innayatullah
Keyword(s):  
Acoustic Emission ◽  
Failure Mechanism ◽  
Fatigue Failure ◽  
Quantitative Relationship ◽  
Steel Specimen ◽  
Cyclic Fatigue ◽  
Steel Component ◽  
Specific Data ◽  
The Relationship ◽  
Ae Signals

This study was carried out to investigate the relationship between the strain and acoustic emission (AE) signals, thus, to confirm the capability of AE technique to monitor the fatigue failure mechanism of a steel component. To achieve this goal, strain and AE signals were captured on the steel specimen during the cyclic fatigue test.  Both signals were collected using specific data acquisition system by attaching the strain gauge and AE piezoelectric transducer simultaneously at the specimen during the test. The stress loading used for the test was set at 600 MPa, and the specimens were fabricated using the SAE 1045 carbon steel.  The related parameters for both signals were determined at every 2000 seconds until the specimen failed.  It was found that a meaningful correlation of all parameters, i.e. amplitude, kurtosis and energy, was established. Finally, all AE parameters are correlated with the damage values, which have been estimated using the Coffin-Manson model.  Hence, it was suggested that the AE technique can be used as a monitoring tool for fatigue failure mechanism in a steel component.

scholarly journals Internal Leakage Predicition of Hydraulic Spool valves Based on Acoustic Emission Technology

2021 ◽  
Vol 2113 (1) ◽  
pp. 012016
Author(s):  
Fei Song ◽  
Likun Peng ◽  
Jia Chen ◽  
Benmeng Wang
Keyword(s):  
Acoustic Emission ◽  
High Frequency ◽  
Peak Frequency ◽  
Leakage Rate ◽  
High Frequency Band ◽  
Signal Characteristics ◽  
Spool Valves ◽  
The Relationship ◽  
Ae Signals ◽  
Acoustic Emission Technology

Abstract In order to realize the nondestructive testing (NDT) of the internal leakage fault of hydraulic spool valves, the internal leakage rate must be predicted by AE (acoustic emission) technology. An AE experimental platform of internal leakage of hydraulic spool valves is built to study the characteristics of AE signals of internal leakage and the relationship between AE signals and leakage rates. The research results show the AE signals present a wideband characteristic. The main frequencies are concentrated in 30~50 kHz and the peak frequency is around 40 kHz. When the leakage rate is large, there are significant signal characteristics appearing in the high frequency band of 75~100 kHz. The exponent of the root mean square(RMS) of AE signals is positively correlated with the exponent of the leakage rate only if the leakage rate is greater than 2~3 mL/min. This find could be used to predict the internal leakage rate of hydraulic spool valves.

scholarly journals Application of Acoustic Emission Technique to the Evaluation of Coal Seam Hydraulic Flushing Effect

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1705 ◽  
Author(s):  
Rongxi Shen ◽  
Xuan Zhang ◽  
Enyuan Wang ◽  
Hongru Li ◽  
Xu Han ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Coal Seam ◽  
Gas Flow ◽  
Damage Mechanics ◽  
Water Pressure ◽  
Quantitative Relationship ◽  
Practical Significance ◽  
Effect Evaluation ◽  
Permeability Enhancement ◽  
Ae Signals

Hydraulic flushing has the advantages of reducing coal stress and improving coal seam permeability, so it is widely used in high gas outburst coal seams in China. However, the effect evaluation of stress relief and permeability enhancement will be necessary before coal mining. In this paper, an acoustic emission (AE) experiment system of coal seam hydraulic flushing was established, and the AE characteristics of coal during hydraulic flushing were studied. The results show that the changes in AE signals are basically consistent with those in load and water pressure. In addition, the quantitative relationship between the signals and the damage of coal around the borehole is revealed by the theory of damage mechanics. The in-situ AE test of hydraulic flushing was performed in the Liangbei Coal Mine, by measuring gas flow and coal stress simultaneously. The variation of AE activities and the effect evaluation of hydraulic flushing were analyzed. The results reveal that the changes in coal seam stress are basically consistent with those of AE signals. After the flushing has been completed for 1–3 h, the coal seam stress decreases rapidly, and the AE counts and intensity reach the peak. Therefore, this study proposes a new method for evaluating the effect of coal seam hydraulic flushing by AE, which has a very important practical significance.

Acoustic Emission During Athermal Martensitic Transformation in Steels

1990 ◽  
Vol 112 (1) ◽  
pp. 84-91 ◽  
Author(s):  
Xiangying Liu ◽  
Elijah Kannatey-Asibu
Keyword(s):  
Free Energy ◽  
Acoustic Emission ◽  
Martensitic Transformation ◽  
Signal Intensity ◽  
Temperature Derivative ◽  
Process Characteristics ◽  
Ae Signal ◽  
The Relationship ◽  
Ae Signals ◽  
Start Temperature

A relationship developed earlier between acoustic emission signals and the process of athermal martensitic transformation based on the free energy associated with the process is extended and verified experimentally. The relationship is found to model the process characteristics very well. The intensity of AE signal generated during transformation was found to be proportional to the temperature derivative of the fraction of martensite, the cooling rate, and volume of specimen. The AE signal was also found to be related to the carbon content of the steel. During transformation, the signal intensity was found to increase to a peak, and then tail off near the end of the transformation. Values of the martensite start temperature obtained from plots of the total RMS squared AE signals were also found to correlate well with values from the literature.

Research on the AE Characteristic of the Rock with Rockburst Proneness

2014 ◽  
Vol 608-609 ◽  
pp. 689-692
Author(s):  
Mo Xiao Li ◽  
Guang Zhang ◽  
Jing Xi Chen
Keyword(s):  
Acoustic Emission ◽  
Uniaxial Compression ◽  
Rock Mechanics ◽  
Compression Tests ◽  
Entire Process ◽  
The Relationship ◽  
Ae Signals

In this paper, in order to strengthen the prediction of rockburst and inquire the relationship between the rockburst proneness of rock and its AE characteristic, each kind of typical rock of volcanic, sedimentary and metamorphic were selected to doing indoor rock mechanics experiments. Calculate the rockburst proneness of these rocks by uniaxial compression tests. In uniaxial compression, we collect the entire process of AE signals by using acoustic emission instrument, then we analysis the AE characteristics of different rocks to inquire the relationship between the AE characteristic and its rockburst proneness.

The Efficiency Optimization of the Cylindrical Grinding Based on Acoustic Emission Signals

2014 ◽  
Vol 494-495 ◽  
pp. 721-724
Author(s):  
Qi Song
Keyword(s):  
Acoustic Emission ◽  
Newton Method ◽  
Grinding Process ◽  
Stable Point ◽  
Efficiency Optimization ◽  
Cylindrical Grinding ◽  
Grinding Efficiency ◽  
The Relationship ◽  
Ae Signals ◽  
Grinding Time

To improve the efficiency of cylindrical plunge grinding, an optimization of grinding process is developed using the Acoustic emission (AE) signals. The relationship between the grinding feed and grinding depth is established based on the elastic deflection between wheel and workpiece. Acoustic emission (AE) signals are curve fitted through the gauss - Newton method to find the stable point of various grinding processes. Therefore, grinding time of each grinding stage is reduced to improve the grinding efficiency.

scholarly journals Study on the Acoustic Emission Characteristics of Different Rock Types and Its Fracture Mechanism in Brazilian Splitting Test

2021 ◽  
Vol 9 ◽  
Author(s):  
Li Shengxiang ◽  
Xie Qin ◽  
Liu Xiling ◽  
Li Xibing ◽  
Luo Yu ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Rock Fracture ◽  
Peak Frequency ◽  
Test System ◽  
Mineral Particle ◽  
Splitting Test ◽  
Ae Signal ◽  
The Relationship ◽  
Ae Signals ◽  
Internal Fracture

In order to investigate the relationship between rock microfracture mechanism and acoustic emission (AE) signal characteristic parameters under split loads, the MTS322 servo-controlled rock mechanical test system was employed to carry out the Brazilian split tests on granite, marble, sandstone, and limestone, while FEI Quanta-200 scanning electron microscope system was employed to carry out the analysis of fracture morphology. The results indicate that different scales of mineral particle, mineral composition, and discontinuity have influence on the fracture characteristics of rock, as well as the b-value. The peak frequency distribution of the AE signal has obvious zonal features, and these distinct peak frequencies of four types of rock fall mostly in ranges of 0–100 kHz, 100–300 kHz, and above 300 kHz. Due to the different rock properties and mineral compositions, the proportions of peak frequencies in these intervals are also different among the four rocks, which are also acting on the b-value. In addition, for granite, the peak frequencies of AE signals are mostly distributed above 300 kHz for granite, marble, and limestone, which mainly derive from the internal fracture of k-feldspar minerals; for marble, the AE signals with peak frequency are mostly distributed in over 300 kHz, which mainly derive from the internal fracture of dolomite minerals and calcite minerals; AE signals for sandstone are mostly distributed in the range of 0–100 kHz, which mainly derive from the internal fracture of quartz minerals; for limestone, the AE signals with peak frequency are mostly distributed in over 300 kHz, which mainly derive from the internal fracture of granular-calcite minerals. The relationship between acoustic emission signal frequency of rock fracture and the fracture scale is constructed through experiments, which is of great help for in-depth understanding of the scaling relationship of rock fracture.

Acoustic Emission Test on Steel/Composite and Steel/Composite/Steel Built-Up Sections

2011 ◽  
Author(s):  
Rushie Ghimire ◽  
Gary Anderson ◽  
Fereidoon Delfanian
Keyword(s):  
Acoustic Emission ◽  
Tensile Tests ◽  
Glue Line ◽  
Stress And Strain ◽  
Steel Component ◽  
Cumulative Count ◽  
Steel Composite ◽  
Acoustic Emission Test ◽  
Ae Signals ◽  
Composite Steel

Acoustic Emission (AE) has been widely used to monitor and inspect built-up steel/composite sections; primarily at the glue line. AE testing was conducted on steel-composite (SC) and steel-composite-steel (SCS) built-up sections to determine the glue line failure and damage sustained by the inner layer of the built-up section by putting the sensors on the inner and outer layers of the built-up sections. The straight specimens of steel/composite and steel/composite/steel were tested with load applied to only one steel layer. The AE sensors were placed on the outer steel component so that detected signals traveled through the loaded steel, glue lines, and the composite or the loaded steel component, two glue lines, composite and unloaded steel components of the built-up section(s). The AE signals received by the sensors placed on the loaded steel in tension was compared to signals of sensors placed directly opposite on the unloaded steel or composite to determine the effect the steel/composite and steel/composite/steel built-up sections had on the signal. AE signals were also compared to signals generated during tensile tests of steel specimens only and composite specimens only. AE parameters like amplitude, hits, counts, frequency, cumulative count, and rise time of the AE signals were recorded, analyzed, and compared. AE parameters were also compared to traditional material properties (like yield and failure stress and strain). Tested specimens were examined with a microscope and observations were compared and analyzed relative to AE and material parameters, and reported.

Acoustic Emission Monitoring Technology Used in the Ceramics Grinding Cut Depth Control

2011 ◽  
Vol 103 ◽  
pp. 464-468
Author(s):  
Min Wang ◽  
Tao Zan ◽  
Lei Hu ◽  
Jian Zhong Hu ◽  
Xin Yun Zhang
Keyword(s):  
Acoustic Emission ◽  
Material Removal ◽  
Ductile Material ◽  
Precision Grinding ◽  
Depth Control ◽  
Ceramic Grinding ◽  
Fracture Damage ◽  
Cut Depth ◽  
The Relationship ◽  
Ae Signals

Precision grinding on brittle materials accomplished without generating subsurface fracture damage is called ductile-regime grinding. The most important key point for maintaining a ductile material removal regime is to ensure that the cut depth made by grinding process does not exceed the critical cut depth. Through collecting and processing the acoustic emission(AE) signals generated by zirconia (PSZ) ceramic grinding tests, and analyzed the characteristics of AE signals under different grinding parameters. As a result of the experiments described in this paper, it can be concluded that AE signals measured during micro-grinding are sensitive to the changes of cut d- epths. The relationship between AE signals and material removal regime could lead to an in-process sensing strategy of the cut depths for ensuring grinding processes under ductile regime.

AE Identification of Flanged Connection Condition in Vibration Environment

2012 ◽  
Vol 517 ◽  
pp. 836-843
Author(s):  
Ning Wang ◽  
Yong Yao ◽  
Jun Lin Tao ◽  
Lin Long
Keyword(s):  
Acoustic Emission ◽  
Energy Spectrum ◽  
Frequency Band ◽  
Wavelet Packet ◽  
Rate Of Change ◽  
Wavelet Packet Decomposition ◽  
Structure Condition ◽  
Relationship Of ◽  
The Relationship ◽  
Ae Signals

On the basis of vibration testing of flanged connection structure, AE signals gathered are carried on processing with MATLAB,mainly the reconstructed signals. The concepts of characteristic frequency band and the superiority frequency band are drawn, and the layers of wavelet packet decomposition are determined, and the frequency band distributed characteristics of acoustic emission (AE) are obtained. With the percentage of wavelet packet energy band, the strengths of superiority frequency band and the relationship of torque and it are gotten quantitatively and it is found that the energy has certain regularity with the torque changing, and proposed that express its rule characteristic with wavelet packet energy spectrum rate of change this target in order to achieve the identification of the connection structure condition.

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