scholarly journals COMPARATIVE EVALUATION OF POLYMERIC MATERIALS FOR THE REMOVABLE DENTURES BASIS BY THE RESULTS OF EXPERIMENTAL STUDIES ON TENSILE OF ACOUSTIC EMISSION METHOD

2019 ◽  
Vol 1 (1) ◽  
pp. 225
Author(s):  
V. F. Makeev ◽  
V. R. Skalskyi ◽  
Ya. R. Hunovskyi
Keyword(s):  
Acoustic Emission ◽  
Comparative Evaluation ◽  
Experimental Studies ◽  
Polymeric Materials ◽  
Acoustic Emission Method ◽  
Emission Method

scholarly journals APPLICATION OF ACOUSTIC EMISSION METHOD FOR THE EVALUATION OF THE MICROMECHANICS OF DESTRUCTION OF FIBERGLASS MATERIALS UNDER STATIC LOAD

Aviation ◽  
2020 ◽  
Vol 24 (4) ◽  
pp. 169-176
Author(s):  
Margarita Urbaha ◽  
Konrad Stefański ◽  
Mukharbiy Banov ◽  
Vladimir Shestakov
Keyword(s):  
Acoustic Emission ◽  
Damage Accumulation ◽  
Static Load ◽  
Experimental Studies ◽  
External Environment ◽  
Design Feature ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Proportional Change ◽  
Two Stages

The paper presents the results of experimental studies using the acoustic emission method of samples made of fiberglass, the design feature of which is the presence of both base fibers and weft fibers. The test data are presented in relative units and the concept of staged damage accumulation is used, which allows one to recognize subtle phenomena of the nature of the destruction of fiberglass. Tests of the samples with a transverse arrangement of fibers with respect to the applied load showed that the fracture process both in the strain parameters and in the parameters of the total acoustic emission has two stages of damage accumulation: the stage of proportional change of these parameters from stress and the stage of intensive increment of these parameters. In this case, the parameter of the total acoustic emission shows that this process of destruction begins earlier by 5–6% than the strain parameter shows. The proposed methodology and equipment allows us to identify the nature of fracture and assess the tensile strength of such a “staged” composition, and also to solve the problem of what affected the structural unity violations, which may be due to the presence of a set of cracks formed during manufacturing or under the influence of stresses and the external environment during the process of loading.

scholarly journals ACOUSTIC EMISSION TESTING OF FIBERGLASS PIPES AND FITTINGS

2021 ◽  
pp. 12-25
Author(s):  
S. V. Elizarov ◽  
D. A. Terentyev ◽  
K. A. Medvedev ◽  
V. I. Ivanov ◽  
A. G. Halimov ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Residual Life ◽  
Early Stage ◽  
Experimental Studies ◽  
Operating Mode ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Dimensional Inspection ◽  
Emission Testing ◽  
Acoustic Emission Testing

Experimental studies was carried out. The purpose was to develop a method to test fiberglass pipelines in operating mode. The acoustic emission method was chosen as the main method of nondestructive testing, and visual and dimensional inspection was chosen as an additional method. Acoustic parameters and acoustic emission properties of fiberglass pipes were determined. It was found that acoustic emission sensors can be installed at distances of up to 9-18 m from each other. A series of loading tests was carried out to refine the methodology. Every loading case was performed until leakage registration. In most cases, leakage occurred near the fillet at pressures of 2.2…3.0 from the working pressure, which indicates a large margin of safety for fiberglass pipes. It is confirmed that the acoustic emission method allows early defect detection. Based on the acoustic emission data, 4 main stages of fiberglass pipes degradation were identified. Visual and dimensional inspection was informative only at stages III – IV. Stage IV in most cases corresponds to the leakage. Even early stage of depressurization was registered as continuous acoustic emission. Signals with amplitudes exceeding 60…80 dB were registered at all loading stages. The location map became informative after filtering events by acoustic emission parameters. A methodology for the testing of fiberglass pipes and fittings in operating mode was developed. It contains, in contrast to the currently valid standards, specific numerical values of various quantities related to both the preparation and carrying out of acoustic emission testing and the classification of the identified sources of acoustic emission according to the degree of danger and allows to evaluate the residual life of fiberglass pipelines. The most informative parameter was the activity of acoustic emission; therefore, it is recommended to carry out loading without holding the pressure. It is planned to carry out additional experiments to clarify the mechanisms of fracture acting at each of the 4 identified stages of degradation.

scholarly journals Monitoring of the Impact of Lithium Nitrate on the Alkali–aggregate Reaction Using Acoustic Emission Methods

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 20
Author(s):  
Justyna Zapała-Sławeta ◽  
Grzegorz Świt
Keyword(s):  
Acoustic Emission ◽  
Initial Reaction ◽  
Lithium Nitrate ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Acoustic Activity ◽  
Initial Stage ◽  
Chemical Admixture ◽  
Different Characteristics ◽  
The Impact

The study analyzed the possibility of using the acoustic emission method to analyse the reaction of alkali with aggregate in the presence of lithium nitrate. Lithium nitrate is a chemical admixture used to reduce adverse effects of corrosion. The tests were carried out using mortars with reactive opal aggregate, stored under the conditions defined by ASTM C227. The acoustic activity of mortars with a corrosion inhibitor was referred to linear changes and microstructure of specimens in the initial reaction stages. The study found a low acoustic activity of mortars with lithium nitrate. Analysis of characteristic parameters of acoustic emission signals, combined with the observation of changes in the microstructure, made it possible to describe the corrosion processes. As the reaction progressed, signals with different characteristics were recorded, indicating aggregate cracking at the initial stage of the reaction, followed by cracking of the cement paste. The results, which were referred to the acoustic activity of reference mortars, confirmed that the reaction of opal aggregate with alkali was mitigated in mortars with lithium nitrate, and the applied acoustic emission method enabled the detection and monitoring of ASR progress.

Three-Point Bending Test Evaluation of Concrete Specimens by Non-Traditional Analysis of Acoustic Emission Method

2016 ◽  
Vol 837 ◽  
pp. 198-202
Author(s):  
Luboš Pazdera ◽  
Libor Topolář ◽  
Tomáš Vymazal ◽  
Petr Daněk ◽  
Jaroslav Smutny
Keyword(s):  
Acoustic Emission ◽  
Signal Analysis ◽  
Measurement Data ◽  
Bending Test ◽  
Test Evaluation ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Three Point Bending ◽  
Time Frequency ◽  
Emission Signal

The aim of the paper is focused on the analysis of the mechanical properties of the concrete specimens with plasticizer at three point bending test by the signal analysis of the acoustic emission signal. The evaluations were compared the measurement and the results obtained with theoretical presumptions. The Joint Time Frequency Analysis applied on measurement data and its evaluation is described. It is well known that the Acoustic Emission Method is a very sensitive method to determine active cracks into structure. However, evaluation of acoustic emission signals is very difficult. A non-traditional method was used to signal analysis of burst acoustic emission signals recorded during three point bending test.

Evaluation of Friction Phenomena of Brake Pads by Acoustic Emission Method

2014 ◽  
Vol 7 (2) ◽  
pp. 703-709 ◽  
Author(s):  
Kazuho Mizuta ◽  
Yukio Nishizawa ◽  
Koji Sugimoto ◽  
Katsuya Okayama ◽  
Alan Hase
Keyword(s):  
Acoustic Emission ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Brake Pads

scholarly journals Characterization of Fatigue Damage in 304L Steel by an Acoustic Emission Method

2013 ◽  
Vol 66 ◽  
pp. 651-660 ◽  
Author(s):  
A. Ould Amer ◽  
A.-L. Gloanec ◽  
S. Courtin ◽  
C. Touze
Keyword(s):  
Acoustic Emission ◽  
Fatigue Damage ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
304L Steel
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