List of publications in 2016, in which our employees participated:
Vera Barat, Dmitrii Chernov, Sergey Elizarov, Igor Vasilyev. AE testing of composite materials: approaches to data analysis, location and evaluation criteria. Proceedings of the 32st Conference of the European Working Group on Acoustic Emission, Prague, 07-09 September 2016 https://www.ndt.net/article/ewgae2016/papers/201_paper.pdf (full text)
Abstract
Composite materials are very widespread in aerospace, refinery and chemical industries. The wide application may be explained by the improved mechanical properties – ultimate tensile strength, flexural modulus and small specific density. The nondestructive evaluation of the composite materials is an actual and complicate problem. Traditional ultrasonic, thermal and electromagnetic NDT methods have a limited application which is explained by anisotropic properties of the composite materials. This study focuses on the problems of acoustic emission arising during the composite materials testing. In the case of the composite materials AE testing has a set of specific features, for example, high AE activity even at the beginning of the structure loading, diversity of AE signals waveforms and spectra from the different AE source (fiber breakage, matrix cracking, destruction of the adhesive layer). Novel AE data registration method adapted for composite materials was offered in this study. This method takes into account the multiform and multiscale character of AE data. It allows separating AE impulses from the different sources – fiber and matrix and as result – estimating the intensity of destruction for each component of the composite material separately. Authors also proposed improved criteria and improved location algorithm for the composite materials.
Vladimir V. Bardakov, Alexander I. Sagaidak. Forecasting of concrete strength during the hardening process by means of Acoustic Emission method. Progress in Acoustic Emission XVIII. Proceedings of the 23rd International Acoustic Emission Symposium, the Inauguration Conference of International Institute of Innovative Acoustic Emission & the 8th International Conference on Acoustic Emission (IAES-23, IIIAE2016 and ICAE-8), December 5-9, 2016, Kyoto. Pp. 105-110
Abstract
The process of concrete structure formation has been studied using the acoustic emission method. Following the results of experimental studies performed, the dependence has been revealed between the acoustic emission data recorded in the first day of concrete composition hardening and its strength at 28 days. The informational parameters of acoustic emission data which correlate with the concrete strength at 28 days have been determined.
Chernov D.V., Barat V.A., Elizarov S.V. Determining the Stages of the Composite Vessel Destruction on the Basis of the Acoustic Emission Testing Results. In: International academic forum АМО – SPITSE – NESEFF. Proceedings of the International Academic Forum AMO – SPITSE – NESEFF. Smolensk. С. 93-94. eLibrary ID: 26444963
Abstract
Composite materials are very widespread in aerspace, reinfinery and chemical industries. The nondesctructive evaluation of the composite materials is an actual and complicate problem. Traditional ultrasonic, thermal and electromagnetic NDT methods have a limited application which is explained by anisopropic properties of the composite materials. This study focuses on the problems of acoustic emission arrising during the composite materials testing.
Sergey Elizarov, Alexander Alyakritsky, Pavel Trofimov, Alexey Bugankov. The New Hardware Features of A-Line 32D AE Systems. Proceedings of the 32st Conference of the European Working Group on Acoustic Emission, Prague, 07-09 September 2016 https://www.ndt.net/article/ewgae2016/papers/109_paper.pdf (full text)
Abstract
The new type of AE system A-Line DS ("Digital Sensor"), which combines centralized data processing scheme and the transmission of the primary digital flow to the acquisition unit data processing, is described. The signal from the AE sensor is amplified and digitized in the Converter ALC ("A-Line Converter") in the immediate vicinity of the sensor, and then the primary flow in the form of a continuous digital high-speed stream is transmitted via a separate coaxial cable to the central unit for collecting and processing data. The computer boards for data acquisition and processing calculates AE parameters in the central unit. DS technology significantly improves noise immunity, accuracy and reliability of AE testing. Currently being tested 16-channel a working prototype of the system A-Line DS with the following features: the ADC has 16 bit and 10 MHz, length of the coaxial line of each channel is 200 m, speed of the digital transmission of primary data of AE up to 280 Mbps, galvanic isolation of each channel is completed; supply voltage of ALC equals 6V.
S.V.Elizarov, V.A.Barat, V.V.Bardakov, D.V.Chernov, D.A. Terentyev. Features of the AE testing of equipment in operating mode. Proceedings of the 32st Conference of the European Working Group on Acoustic Emission, Prague, 07-09 September 2016 https://www.ndt.net/article/ewgae2016/papers/115_paper.pdf (full text)
Abstract
The possibility of AE testing of roller supports of the rotary kiln in operating mode was investigated in the alumina refinery in the sintering and calcining shops. Each roller support consists of a shaft, roller and bearing blocks. Each element is entitled to be tested. Research task was to assess the possible locations of damage, filtering of in-plant noises, and identification of the damage type. By simulating AE signals it was discovered that the ratio of amplitudes at different AE sensors allows to determine the location of damage within the accuracy of the structural node. Linear location of AE sources is possible only within the shaft. It was revealed that the only significant source of the high amplitude impulsive noise in operating mode are scuffs and roughness on the roller surface or kiln tyre. Impulses corresponded to noise are recorded with the period which is equal to the rotation interval of the support, or the kiln, so such impulses can be easily filtered. Detected defects of shaft can be divided into 2 types. Defects of the first type correspond to fatigue cracks and are located as a rule in places with the highest concentration of stresses such as fillet transitions. The second type presumably corresponds to the shaft surface deterioration at friction contact. The amplitude distribution parameters of impulses that characterize this process correlate with the working lifespan of the roller supports. Bearing defects are more diverse. Such defects as inner bearing race cracks, brinelling, and violation of lubrication rate were identified in the AE data on the basis of information about known defects.
S. Elizarov, V. Bardakov, V. Barat, D. Terentyev, D. Chernov. Features of the AE Method Use in Monitoring of Bridge Structures. Progress in Acoustic Emission XVIII. Proceedings of the 23rd International Acoustic Emission Symposium, the Inauguration Conference of International Institute of Innovative Acoustic Emission & the 8th International Conference on Acoustic Emission (IAES-23, IIIAE2016 and ICAE-8), December 5-9, 2016, Kyoto. Pp. 99-104
Abstract
The experiment results of estimating the efficiency of acoustic emission (AE) method application for monitoring the highway bridge structures have been presented in this paper. The main difficulties arising during monitoring of the similar kind of objects have been considered. An extremely high level of the acoustic noise has been recorded. The method of noise suppression has been offered. In addition, the probability of detecting the acoustic emission sources with various distances between transducers has been estimated.
Matyunin V.M., Barat V.A., Bardakov V.V., Marchenkov A.Yu. Assessment of Fracture Toughness of Hardening Coatings by Instrumented Indentation and Acoustic Emission Parameters. In: International academic forum АМО – SPITSE – NESEFF. Proceedings of the International Academic Forum AMO – SPITSE – NESEFF. Smolensk. 2016. С. 95-96. eLibrary ID: 26444964
Abstract
The possibility of effective application of instrumented indentation method together with Acoustic Emission (AE) method for evaluation of fracture toughness of hardening coatings is described in the article. It has been established that the presence of one of the fractures on the instrumented indentation diagram line on the axes “load - indent displacement - time” can be explained by appearance of the first crack in the coating and it almost coincides in time with appearance of acoustic emission impulse with the increasing of energy rate.
Sokolov, Igor V.; Matyunin, Vyacheslav M.; Barat, Vera A.; Chernov, Dmitriy V.; Marchenkov, Artem Yu. Advanced Filtering Methods Application for Sensitivity Enhancement during AE Testing of Operating Structures. Indian Journal of Science and Technology, 2016, 9, 42. DOI: 10.17485/ijst/2016/v9i42/104223 (full text). https://indjst.org/download-article.php?Article_Unique_Id=INDJST8562&Full_Text_Pdf_Download=True (full text). eLibrary ID: 27581269
Abstract
The article considers different filtering methods for acoustic emission data. The discussion of data filtering algorithms is aimed at improving the noise immunity of the acoustic emission system. Method: Noise filtering methods (frequency filtering, time series disorder detection, etc.) are examined for AE testing. Findings: One problem of the acoustic emission testing is a great number of noises affecting the diagnosis results. Electric noises, electromagnetic interference, background acoustic noise, rubbing noises are far from the full list of noises available during measurements. At the high level of noises, the operator has to increase the recording threshold of the acoustic emission impulses through reducing the testing sensitivity at the risk of missing a dangerous defect. Lack of the data filtering can result in an incorrect localization and erroneous definition of the danger level of acoustic emission source. Different noise types have been investigated and noise classification method according to the filtering complexity has been suggested to solve effectively the problem of the acoustic emission test data filtering. Wavelet-filtering efficiency for white stochastic noise removal has been shown. Algorithm for impulse noise filtering has been described. Improvements: The offered data processing approaches allow enhancing the sensitivity of AE testing especially for the operating structures.
Barat V.A., Chernov D.V., Elizarov S.V. Discovering data flow discords for enhancing noise immunity of acoustic-emission testing. Russian Journal of Nondestructive Testing, 2016, 52, 6, pp. 347-356. DOI: 10.1134/S1061830916060024. eLibrary ID: 27136728
Abstract
A new approach has been suggested to revealing acoustic-emission data-flow discords that are related to the formation and growth of flaws. The discords were discovered using a statistical criterion and the Caterpillar SSA principal components method. The approach has proved its consistency when tested on realistic acoustic-emission data-flow models.
Yu. G. Matvienko, I. E. Vasil’ev, V. I. Ivanov, and S. V. Elizarov. Acoustic-Emission Evaluation of the Process of Destruction of a Composite Material under Tensile, Compression, and Cyclic Loads. Russian Journal of Nondestructive Testing, 2016, Vol. 52, No. 8, pp. 443–456. DOI: 10.1134/S1061830916080076. eLibrary ID: 27573116
Abstract
Destruction of the structure of polymer composite materials (PCMs) has been studied by acoustic-emission evaluation method under tensile, compression, and alternating-sign cyclic loads. A program of cluster classification of registered data arrays has been developed and used to reveal specific AE signals that are typical of studied load types. Detection of such signals in the course of deformation of the test samples indicates that irreversible structural changes occur in the composite, it is losing its carrying capacity, or a predestruction state that is critical for PCM has been reached.
Makhutov, N. A.; Vasil’ev, I. E.; Ivanov, V. I.; Elizarov, S. V.; Chernov, D. V. Testing the Technique for the Cluster Analysis of Acoustic Emission Pulse Arrays under the Formation of a Conical Glass Granulate Pile. Inorganic Materials, 2017, 53, 15, pp. 1513-1524. DOI: 10.1134/S0020168517150080. eLibrary ID: 35498806
Abstract
The technique for the cluster analysis and the classification of registered acoustic emission (AE) data arrays was used for the determination of the isolated phases upon the transition from the regular to the avalanche process of damage accumulation in a physical simulation model. The damage accumulation phases were modeled in the process of formation of a conical glass granulate pile. Their registration was performed by an AE control system synchronized with a high-speed video camera.