Mechanical properties of friction welds of RAFs (JLF-1) to SUS304 steels as measured by the acoustic emission technique

The behavior of rock mass is governed by the properties of both the rock material and discontinuities in the rock mass. Surrounding environments including the existence of water also have a great influence on the behavior and mechanical properties of rocks. In this study, a novel-designed compression and seepage testing system, associated with an acoustic emission system, was designed and constructed. The changes in the specimens resulting from the uniaxial compression were monitored by an acoustic emission technique. The characteristics of the acoustic emission parameters at different stages including compaction and crack initiation, crack propagation, and catastrophic failure were analyzed. The existence of seepage had direct influences on the mechanical properties and failure patterns of the specimens. The specimens tested in pure compression conditions demonstrated strong burst proneness and ruptured into separate pieces, while for the specimens with seepage, no burst proneness was observed and the specimens tended to fail along a macroscopic shear failure plane. The highest average energy of the acoustic signal occurred at the stage of initial rupture of rock specimens, rather than at the stage of widespread rupture. The studies explored the possibilities of using the acoustic emission technique to investigate the problems associated with the seepage in geotechnical and rock engineering and provided meaningful results for further research in this field.

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Rate effect on mechanical properties of hydraulic concrete flexural-tensile specimens under low loading rates using acoustic emission technique

Ultrasonics ◽

10.1016/j.ultras.2012.02.011 ◽

2012 ◽

Vol 52 (7) ◽

pp. 890-904 ◽

Cited By ~ 20

Author(s):

Huaizhi Su ◽

Jiang Hu ◽

Jianjie Tong ◽

Zhiping Wen

Keyword(s):

Mechanical Properties ◽

Acoustic Emission ◽

Rate Effect ◽

Acoustic Emission Technique ◽

Loading Rates ◽

Hydraulic Concrete

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Comparison of macroscopic mechanical properties and shear band characteristics established by acoustic emission measurements in Fe85-xCoxB15 amorphous alloys ribbons

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:2001532 ◽

2001 ◽

Vol 11 (PR5) ◽

pp. Pr5-259-Pr5-265 ◽

Cited By ~ 1

Author(s):

E. D. Tabachnikova ◽

A. Yu. Vinogradov

Keyword(s):

Mechanical Properties ◽

Acoustic Emission ◽

Shear Band ◽

Amorphous Alloys

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Optimizing the Acoustic-Emission Technique for Examining the Strength of Welded Joints

Vestnik MEI ◽

10.24160/1993-6982-2017-2-96-101 ◽

2017 ◽

pp. 96-101

Author(s):

Viktor V. Nosov ◽

◽

Alsu R. Yamilova ◽

Nikolay A. Zelenskiy ◽

Ilya V. Matviyan ◽

...

Keyword(s):

Acoustic Emission ◽

Welded Joints ◽

Acoustic Emission Technique

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Experience with the use of the acoustic emission technique for monitoring scale failure in wet and dry environments

Materials at High Temperatures ◽

10.3184/096034005782750491 ◽

2005 ◽

Vol 22 (1) ◽

pp. 35-45 ◽

Cited By ~ 6

Author(s):

Daniel Renusch ◽

Michael Schütze

Keyword(s):

Acoustic Emission ◽

Acoustic Emission Technique ◽

Scale Failure

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Study on mechanical properties and damage evolution of carbonaceous shale under triaxial compression with acoustic emission

International Journal of Damage Mechanics ◽

10.1177/1056789521991193 ◽

2021 ◽

pp. 105678952199119

Author(s):

Kai Yang ◽

Qixiang Yan ◽

Chuan Zhang ◽

Wang Wu ◽

Fei Wan

Keyword(s):

Mechanical Properties ◽

Acoustic Emission ◽

Water Content ◽

Damage Evolution ◽

Damage Assessment ◽

Triaxial Compression ◽

Confining Pressure ◽

Damage Variable ◽

Natural State ◽

Carbonaceous Shale

To explore the mechanical properties and damage evolution characteristics of carbonaceous shale with different confining pressures and water-bearing conditions, triaxial compression tests accompanied by simultaneous acoustic emission (AE) monitoring were conducted on carbonaceous shale rock specimens. The AE characteristics of carbonaceous shale were investigated, a damage assessment method based on Shannon entropy of AE was further proposed. The results suggest that the mechanical properties of carbonaceous shale intensify with increasing confining pressure and degrade with increasing water content. Moisture in rocks does not only weaken the cohesion but also reduce the internal friction angle of carbonaceous shale. It is observed that AE activities mainly occur in the post-peak stage and the strong AE activities of saturated carbonaceous shale specimens appear at a lower normalized stress level than that of natural-state specimens. The maximum AE counts and AE energy increase with water content while decrease with confining pressure. Both confining pressure and water content induce changes in the proportions of AE dominant frequency bands, but the changes caused by confining pressure are more significant than those caused by water content. The results also indicate that AE entropy can serve as an applicable index for rock damage assessment. The damage evolution process of carbonaceous shale can be divided into two main stages, including the stable damage development stage and the damage acceleration stage. The damage variable increases slowly accompanied by a few AE activities at the first stage, which is followed by a rapid growth along with intense acoustic emission activities at the damage acceleration stage. Moreover, there is a sharp rise in the damage evolution curve for the natural-state specimen at the damage acceleration stage, while the damage variable develops slowly for the saturated-state specimen.

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Acoustic Emission and K-S Metric Entropy as Methods for Determining Mechanical Properties of Composite Materials

Sensors ◽

10.3390/s21010145 ◽

2020 ◽

Vol 21 (1) ◽

pp. 145

Author(s):

Lesław Kyzioł ◽

Katarzyna Panasiuk ◽

Grzegorz Hajdukiewicz ◽

Krzysztof Dudzik

Keyword(s):

Mechanical Properties ◽

Acoustic Emission ◽

Composite Material ◽

Composite Materials ◽

Testing Machine ◽

Measurement Data ◽

Entropy Method ◽

Displacement Sensor ◽

Metric Entropy ◽

Plastic Phase

Due to the unique properties of polymer composites, these materials are used in many industries, including shipbuilding (hulls of boats, yachts, motorboats, cutters, ship and cooling doors, pontoons and floats, torpedo tubes and missiles, protective shields, antenna masts, radar shields, and antennas, etc.). Modern measurement methods and tools allow to determine the properties of the composite material, already during its design. The article presents the use of the method of acoustic emission and Kolmogorov-Sinai (K-S) metric entropy to determine the mechanical properties of composites. The tested materials were polyester-glass laminate without additives and with a 10% content of polyester-glass waste. The changes taking place in the composite material during loading were visualized using a piezoelectric sensor used in the acoustic emission method. Thanks to the analysis of the RMS parameter (root mean square of the acoustic emission signal), it is possible to determine the range of stresses at which significant changes occur in the material in terms of its use as a construction material. In the K-S entropy method, an important measuring tool is the extensometer, namely the displacement sensor built into it. The results obtained during the static tensile test with the use of an extensometer allow them to be used to calculate the K-S metric entropy. Many materials, including composite materials, do not have a yield point. In principle, there are no methods for determining the transition of a material from elastic to plastic phase. The authors showed that, with the use of a modern testing machine and very high-quality instrumentation to record measurement data using the Kolmogorov-Sinai (K-S) metric entropy method and the acoustic emission (AE) method, it is possible to determine the material transition from elastic to plastic phase. Determining the yield strength of composite materials is extremely important information when designing a structure.

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