scholarly journals Mechanical Behavior and Plastic Instabilities of Compressed Al Metals and Alloys Investigated with Intensive Strain and Acoustic Emission Methods

10.5772/19694 ◽  
2011 ◽  
Author(s):  
Andrzej Pawelek
Keyword(s):  
Acoustic Emission ◽  
Mechanical Behavior ◽  
Metals And Alloys

scholarly journals Influence of SiC Addition on Mechanical Behavior of Thermal Barriers with the Aid of Acoustic Emission

2021 ◽  
Vol 5 (1) ◽  
pp. 16
Author(s):  
David Jeronimo Busquets ◽  
Carlos Bloem ◽  
Amparo Borrell ◽  
Maria Dolores Salvador
Keyword(s):  
Acoustic Emission ◽  
Mechanical Behavior ◽  
Thermal Barrier Coatings ◽  
Wavelet Transforms ◽  
Coefficient Of Thermal Expansion ◽  
Microstructural Analysis ◽  
Thermal Barrier ◽  
Transfer Coefficients ◽  
Barrier Coatings ◽  
Thermal Barriers

The improvement of high temperature materials with lower heat transfer coefficients lead to the development of thermal barrier coatings (TBCs). One of the most widely used materials for thermal barrier coatings is Y2O3 stabilized ZrO2 (Y-TZP) because of its excellent shock resistance, low thermal conductivity, and relatively high coefficient of thermal expansion. The aim of this work is to study the TBCs mechanical behavior with the addition of SiC into the suspension of Y-TZP/Al2O3 by acoustic emission (AE). Additionally, a microstructural analysis and a finite elements model were carried out in order to compare results. The coatings were made by suspension plasma spray (SPS) on metal plates of 70 × 12 × 2 mm3. An intermetallic was deposited as a bond coating, followed by a coating of Y-TZP/Al2O3 with and without 15 wt.% SiC, with thicknesses between 87 and 161 μm. The AE becomes a fundamental tool in the study of the mechanical behavior of thermal barriers. The use of wavelet transforms streamlines the study and analysis of recorded sound spectra. The crack generation arises at very low stress levels.

scholarly journals Comparison of Mechanical Behavior and Acoustic Emission Characteristics of Three Thermally-Damaged Rocks

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2350 ◽  
Author(s):  
Jun Peng ◽  
Sheng-Qi Yang
Keyword(s):  
Mechanical Properties ◽  
Acoustic Emission ◽  
Mechanical Behavior ◽  
Thermal Damage ◽  
Strain Curve ◽  
Treatment Temperature ◽  
P Wave ◽  
High Temperature Treatment ◽  
High Porosity ◽  
Compression Tests

High temperature treatment has a significant influence on the mechanical behavior and the associated microcracking characteristic of rocks. A good understanding of the thermal damage effects on rock behavior is helpful for design and stability evaluation of engineering structures in the geothermal field. This paper studies the mechanical behavior and the acoustic emission (AE) characteristic of three typical rocks (i.e., sedimentary, metamorphic, and igneous), with an emphasis on how the difference in rock type (i.e., porosity and mineralogical composition) affects the rock behavior in response to thermal damage. Compression tests are carried out on rock specimens which are thermally damaged and AE monitoring is conducted during the compression tests. The mechanical properties including P-wave velocity, compressive strength, and Young’s modulus for the three rocks are found to generally show a decreasing trend as the temperature applied to the rock increases. However, these mechanical properties for quartz sandstone first increase to a certain extent and then decrease as the treatment temperature increases, which is mainly attributed to the high porosity of quartz sandstone. The results obtained from stress–strain curve, failure mode, and AE characteristic also show that the failure of quartz-rich rock (i.e., quartz sandstone and granite) is more brittle when compared with that of calcite-rich rock (i.e., marble). However, the ductility is enhanced to some extent as the treatment temperature increases for all the three examined rocks. Due to high brittleness of quartz sandstone and granite, more AE activities can be detected during loading and the recorded AE activities mostly accumulate when the stress approaches the peak strength, which is quite different from the results of marble.

Fatigue behavior and damage analysis by the acoustic emission technique of cross-ply laminates under tensile loading

2017 ◽  
Vol 13 (2) ◽  
pp. 150-164
Author(s):  
Imen Ben Ammar ◽  
Abderrahim El Mahi ◽  
Chafik Karra ◽  
Rachid El Guerjouma ◽  
Mohamed Haddar
Keyword(s):  
Acoustic Emission ◽  
Mechanical Behavior ◽  
Fatigue Behavior ◽  
Glass Fibers ◽  
Tensile Tests ◽  
Hybrid Fibers ◽  
Content Type ◽  
Laminated Materials ◽  
Ae Signals ◽  
Damage Investigation

Purpose The purpose of this paper is to study the mechanical behavior in fatigue tensile mode of different cross-ply laminates constituted of unidirectional carbon fibers, hybrid fibers and glass fibers in an epoxy matrix; and to identify and characterize the local damage in the laminated materials with the use of the acoustic emission (AE) technique. Design/methodology/approach The tests in the fatigue mode permitted the determination of the effect of the stacking sequences, thickness of 90° oriented layers and reinforcement types on the fatigue mechanical behavior of the laminated materials. The damage investigation in those materials is reached with the analysis of AE signals collected from fatigue tensile tests. Findings The results show the effects of reinforcement type, stacking sequences and thicknesses ratio of 90° and 0° layers on the mechanical behavior. A cluster analysis of AE data is achieved and the resulting clusters are correlated with the damage mechanism of specimens under loading tests. Originality/value The analysis of AE signals collected from tensile tests of the fatigue failure load allows the damage investigation in different types of cross-ply laminates which are differentiated by the reinforcement type, stacking sequences and thicknesses ratio of 90° and 0° layers.

Acoustic-emission monitoring of hydrogen cracking in metals and alloys

1993 ◽  
Vol 28 (4) ◽  
pp. 378-382 ◽  
Author(s):  
A. E. Andreikiv ◽  
N. V. Lysak ◽  
V. R. Skal'skii ◽  
I. L. Parasyuk ◽  
O. N. Sergienko
Keyword(s):  
Acoustic Emission ◽  
Metals And Alloys ◽  
Hydrogen Cracking ◽  
Acoustic Emission Monitoring ◽  
Emission Monitoring

Effect of graphite addition on mechanical behavior of Al6061/TiB2 hybrid composite using acoustic emission

2014 ◽  
Vol 612 ◽  
pp. 16-27 ◽  
Author(s):  
S. Suresh ◽  
N. Shenbaga Vinayaga Moorthi ◽  
S.C. Vettivel ◽  
N. Selvakumar ◽  
G.R. Jinu
Keyword(s):  
Acoustic Emission ◽  
Mechanical Behavior ◽  
Hybrid Composite

scholarly journals Dynamic Mechanical Behavior of Dry and Water Saturated Igneous Rock with Acoustic Emission Monitoring

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Jun Guo ◽  
Guo-rui Feng ◽  
Ting-ye Qi ◽  
Pengfei Wang ◽  
Jian Yang ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Cyclic Loading ◽  
Mechanical Behavior ◽  
Igneous Rock ◽  
Water Injection ◽  
Brittle Behavior ◽  
Cyclic Loading And Unloading ◽  
Cyclic Loading Tests ◽  
Water Saturated ◽  
Water Contents

The uniaxial cyclic loading tests have been conducted to study the mechanical behavior of dry and water saturated igneous rock with acoustic emission (AE) monitoring. The igneous rock samples are dried, naturally immersed, and boiled to get specimens with different water contents for the testing. The mineral compositions and the microstructures of the dry and water saturated igneous rock are also presented. The dry specimens present higher strength, fewer strains, and rapid increase of AE count subjected to the cyclic loading, which reflects the hard and brittle behavior and strong burst proneness of igneous rock. The water saturated specimens have lower peak strength, more accumulated strains, and increase of AE count during the cyclic loading. The damage of the igneous rocks with different water contents has been identified by the Felicity Ratio Analysis. The cyclic loading and unloading increase the dislocation between the mineral aggregates and the water-rock interactions further break the adhesion of the clay minerals, which jointly promote the inner damage of the igneous rock. The results suggest that the groundwater can reduce the burst proneness of the igneous rock but increase the potential support failure of the surrounding rock in igneous invading area. In addition, the results inspire the fact that the water injection method is feasible for softening the igneous rock and for preventing the dynamic disasters within the roadways and working faces located in the igneous intrusion area.

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