Papers

List of 109 publications in English, in which our employees participated:

 

 

 

 

 

 

2023:

V. Barat, V. Bardakov, S. Elizarov. Probability of detecting fatigue cracks in pearlitic steels by acoustic emission method. World Conference on Acoustic Emission (WCAE-2023), Chengdu, China. November 14-17 2023

S. Elizarov. The overview of the INTERUNIS-IT product line and technologies. World Conference on Acoustic Emission (WCAE-2023), Chengdu, China. November 14-17 2023

Barat V.A., Lenev S.N., Radin Yu.A. Method for determining air suction in the vacuum system of steam turbine plants. Russian patent №2800565 (2023). eLibrary ID: 54232114

Abstract

Field: steam turbines. Substance: invention us intended to determine the suction of air in the vacuum system of steam turbine plants. The temporal realizations of acoustic signals on the surface of the equipment are measured and the amplitude, spectral and correlation criteria for the presence of a leak are calculated, whereas the temporal realizations of acoustic signals are measured at two points of the alleged suction s1, s2 and at two points of the no suction s3,s4 to determine the reference signal, filter the received acoustic signals, determine the stationary sections of acoustic signals, form a sample of temporal realizations of acoustic signals, the amplitude criterion for the presence of suction critA is calculated based on a comparison of the standard deviations of the signals s1, s2, s3, s4, the spectral criterion for the presence of suction critE is calculated based on a comparison of the entropy of the spectra of signals s1, s2 and signals s3, s4, the correlation criterion for the presence of suction critR is obtained based on the calculation of the partial correlation coefficient of signals s1 and s2, excluding the influence of signal s3, after which the weighted integral criterion for the presence of suction cup crit is calculated using the formula crit=α⋅ critA+β⋅ crit+γ⋅ critR, where α ,β ,γ are weight coefficients such that α +β +γ =1, whereas if the crit value is less than 0.5, it is concluded that there is no air suction; if the crit value is in the range of 0.5-0.67, it is concluded that air suction is possible; if the crit value exceeds 0.67, a conclusion is made about the presence of air suction. Effect: increasing the speed of determining air suction in the vacuum system of steam turbine plants, as well as expanding the scope and increasing accuracy

Vasilev I.E., Matvienko Yu.G., Chernov D.V., Makhutov N.A., Elizarov S.V. Method for monitoring the load-bearing capacity of products. Russian patent №2787964 (2023). eLibrary ID: 50129463

Abstract

Field: measuring technology. Substance: invention is used for monitoring the load-bearing strength of products using acoustic emission diagnostics. The essence of the invention lies in the fact that cluster selection of recorded location pulses is carried out in the field of relative energy (Ep) and average emission frequency descriptors (Np/tp, where Np is the number of emissions, tp is the pulse duration) for clusters of the lower (L), middle (M) and upper (U) energy levels, and calculation of the weight content of location pulses (WL, WM, WU) in the specified clusters (Wi = (Ni/N∑)⋅100%, where N∑ is the total number of location pulses, Ni=L, M, U is their number in the i-th cluster), while additionally calculating the current level of load-bearing capacity of products according to the corresponding formulas, which include parameters such as WL and WM: the weight content of location pulses recorded every second in the lower and middle energy clusters, [WL] and [WM] are their threshold values in case of structural material destruction, (WL)max ≥ 80%, (WM)min ≤ 20%, (WU)min < 1% are the extreme values of the parameters recorded during the transition from scattered to local damage accumulation. Effect: increasing the reliability and accuracy of the assessment of the current level of load-bearing capacity of products using AE diagnostics

2022:

V. Barat, A. Marchenkov, V. Bardakov, D. Zhgut, M. Karpova, T. Balandin, S. Elizarov. Assessment of the Structural State of Dissimilar Welded Joints by the Acoustic Emission Method. Appl. Sci. 2022, 12(14), 7213. https://www.mdpi.com/2076-3417/12/14/7213 (full text). DOI: 10.3390/app12147213

Abstract

In this study, we investigated defect detection in dissimilar welded joints by the acoustic emission (AE) method. The study objects were carbide and decarburized interlayers, which are formed at the fusion boundary between austenitic and pearlitic steels. Diffusion interlayers, as a structural defect, usually have microscopic dimensions and cannot be detected using conventional non-destructive testing (NDT) methods. In this regard, the AE method is a promising approach to diagnose metal objects with a complex structure and to detect microscopic defects. In this paper, the AE signatures obtained from testing defect-free specimens and specimens with diffusion interlayers are analyzed. We found that the AE signature for defective and defect-free welded joints has significant differences, which makes it possible to identify descriptors corresponding to the presence of diffusion interlayers in dissimilar welded joints.

 

V. Barat, A. Marchenkov, V. Bardakov, D. Zghut, M. Karpova, S. Elizarov. Diagnostics of Dissimilar Weld Joints of Austenitic to Pearlitic Steels by Acoustic Emission. J. Inst. Eng. India Ser. D. 2022. DOI: 10.1007/s40033-022-00409-y

Abstract

Dissimilar welded joints are widely used nowadays in power engineering industry for manufacturing of pipelines and other power equipment elements. Diagnostics of welding defects in these joints by nondestructive testing (NDT) is quite difficult, since high gradients of chemical composition and microstructure reduce the sensitivity of traditional NDT scanning methods. The paper is devoted to the study of the possibility of AE method application for diagnostics of dissimilar welded joints of pearlitic to austenitic steel. The identification of defects lack of penetration and microstructure defects in the form of diffusion interlayers under cyclic tensile loading of flat specimens with welded joints is considered. As a result of the research, it was found that dissimilar welded joints containing defects are characterized by a specific AE signature. It was established that for welded specimens with lack of penetration and diffusion interlayers, the AE activity turned out to be significantly higher than for defect-free ones. Herewith, specimens with diffusion interlayers are characterized by large amplitude values (up to 70–80 dB), and specimens with lack of penetration are characterized by higher AE activity, while the amplitudes of AE hits did not exceed 60–65 dB. The results obtained can be used for determination of diagnostic criteria for detecting defects by AE method and subsequent development of an industrial NDT technique for dissimilar welded joints under study.

 

V. Barat, A. Marchenkov, S. Ushanov, V. Bardakov, S. Elizarov. Investigation of Acoustic Emission of Cracks in Rails under Loading Close to Operational. Appl. Sci. 2022, 12(22), 11670. https://www.mdpi.com/2076-3417/12/22/11670 (full text). DOI: 10.3390/app122211670

Abstract

The paper is devoted to the study of the possibility of detecting cracks in railway rails by the acoustic emission (AE) method. An experimental study of AE signals under cyclic compression loading of rail fragments, which simulates the rail operating load, has been carried out. Fragments of rails without defects, as well as fragments containing pre-grown fatigue cracks, were studied. It was found that AE signals generated by a rail with a crack have higher activity compared to signals from defect-free specimens. It is shown that the AE signals during the loading of defect-free specimens have a short duration and low amplitude and may be caused by the deformation of non-metallic inclusions. The crack presence leads to an increase in the AE hits rate and changes the nature of the distribution of the AE hits amplitudes. It is shown that the crack location has no effect on the reliability of its detection by the AE method. Criteria of crack detection by AE testing are offered as a result of this study.

 

A. Machikhin, A. Poroykov, V. Bardakov, A. Marchenkov, D. Zhgut, M. Sharikova, V. Barat, N. Meleshko, A. Kren. Combined Acoustic Emission and Digital Image Correlation for Early Detection and Measurement of Fatigue Cracks in Rails and Train Parts under Dynamic Loading. Sensors 2022, 22(23), 9256. https://www.mdpi.com/1424-8220/22/23/9256 (full text). DOI: 10.3390/s22239256

Abstract

Fatigue crack in rails and cyclic-loaded train parts is a contributory factor in multiple railroad accidents. We address the problem of crack detection and measurement at early stages, when total failure has not yet occurred. We propose to combine acoustic emission (AE) testing for prediction of crack growth with digital image correlation (DIC) for its accurate quantitative characterization. In this study, we imitated fatigue crack appearance and growth in samples of railway rail and two train parts by cyclic loading, and applied these two techniques for inspection. Experimental results clearly indicate the efficiency of AE in the early detection of fatigue cracks, and excellent DIC capabilities in terms of geometrical measurements. Combination of these techniques reveals a promising basis for real-time and non-destructive monitoring of rails and train parts.

 

Y. A. Eliovich, V. A. Barat, V. V. Bardakov, A. Y. Marchenkov, D. D. Khokhlov and D. A. Zhgut. Predictive Analysis of Structural Changes in Paratellurite Crystals Using the Acoustic Emission Method. International Conference on Information, Control, and Communication Technologies (ICCT), 2022, pp. 1-5. DOI: 10.1109/ICCT56057.2022.9976555

Abstract

Paratellurite TeO 2 crystals of various degrees of defectiveness were studied under external mechanical loading. The results of structural changes in crystals were obtained by capturing acoustic emission data and polarized optical microscopy observation. Peculiarities of acoustic emission corresponding to defects of various types in crystals are revealed. It has been experimentally shown that acoustic emission monitoring of a mechanically loaded paratellurite makes it possible to assess its structure degree of defectiveness even in the elastic zone. Thus, the possibility of irreversible deformation process also can be predicted.

 

Sagaidak A.I., Bardakov V.V. Method for determining strength of concrete by acoustic emission method. Russian patent №2807868 (2022). eLibrary ID: 56017020

Abstract

Field: construction; concrete mixtures. Substance: scope of the invention relates namely to the control of concrete mixtures of various compositions using the method of acoustic emission signals during the formation of their structure. A method for determining the strength of concrete with chemical and mineral additives using the acoustic emission method is disclosed, which includes determining the parameters of acoustic emission signals and recording the time of their appearance in real time. To implement the method, a deep waveguide with an attached acoustic emission transducer is placed in the concrete mixture. On concrete cubes of different compositions measuring at least 200×200×200 mm the structure formation is monitored, and each composition is duplicated two to three times, and for each composition monitoring is carried out continuously for at least twenty-eight days. Next, the strength characteristics of the concrete are monitored, and the strength of the control cubes is monitored on the 1st, 3rd, 7th, 14th and 28th days of curing. After this, the relationships and dependencies of the informative parameters of the acoustic emission signals between the strength characteristics of concrete are established. Then, the informative parameters of acoustic emission signals, which closely correlate with the strength of concrete, are considered, and the optimal time intervals for measuring acoustic emission are established, which makes it possible to most accurately predict the kinetics of further strength gain of concrete using the acoustic emission method. After this, acoustic emission pulses are recorded in real time, and three stages of structure formation are distinguished, characterized by varying degrees of acoustic emission intensity. The start and end times of the second period are specified in an automated mode, in which the Akaike information criterion is used where AIC is the value of the Akaike criterion coefficient; – dependence of the number of acoustic emission pulses on time; N – duration of the observation interval; k – reference number. In this case, the change in the sign of the derivative of the Akaike function, which corresponds to the disorder of the process, is used as a detection criterion, and the moment when the criterion reaches a minimum is selected as the time. Within the framework of this algorithm, the Akaike criterion is applied twice - to determine the beginning and end of the second stage. Next, set the start and end times of each of the three stages, the parameters and are determined. The parameter is determined as the difference between the obtained values of the beginning and end of the second period, and the slope of the third perioddepending on the sum of acoustic emission pulses versus time. The parameter is determined by the least squares method in a time window, the beginning of which coincides with the beginning of the third stage, and based on the estimated parameters and . Then the strength of concrete is predicted in accordance with predictive models. SP-180 according to TU 20.59.59-003-26025492-2018 or CENTRIPOR TFM 411R are used as chemical additives, and ground and granulated blast furnace slag is used as a mineral additive. Effect: ability to determine the strength of concrete with chemical and mineral additives using the acoustic emission method, and the relative error of using an automated algorithm when predicting strength does not exceed 4.0%.

2021:

Barat V., Marchenkov A., Bardakov V., Karpova M., Kuznetsov M., Zaprudnova A., Ushanov S., Elizarov S., Kritskiy D. Structural health monitoring ofwalking dragline excavator using acoustic emission. Applied Sciences (Switzerland). 2021. Т. 11. № 8. DOI 10.3390/app11083420 (full text). https://www.mdpi.com/2076-3417/11/8/3420 (full text). eLibrary ID: 46021769

Abstract

The article is devoted to the organization of the structural health monitoring of a walking dragline excavator using the acoustic emission (AE) method. Since the dragline excavator under study is a large and noisy industrial facility, preliminary prospecting researches were carried out to conduct effective control by the AE method, including the study of AE sources, AE waveguide, and noise parameters analysis. In addition, AE filtering methods were improved. It is shown that application of the developed filtering algorithms allows to detect AE impulses ffrom cracks and defects against a background noise exceeding the useful signal in amplitude and intensity. Using the proposed solutions in the monitoring of a real dragline excavator during its operation made it possible to identify a crack in one of its elements (weld joint in a dragline back leg).

 

Barat V., Marchenkov A., Bardakov V., Karpova M., Zhgut D., Elizarov S. Features of acoustic emission in tensile testing of dissimilar welded joints of pearlitic and austenitic steels. Applied Sciences (Switzerland). 2021. Т. 11. № 24. DOI: 10.3390/app112411892 (full text). https://www.mdpi.com/2076-3417/11/24/11892 (full text). eLibrary ID: 47542186

Abstract

This paper presents a study of acoustic emission (AE) during the deformation of dissimilar welded joints of austenitic steel to pearlitic steel. One of the specific problems in these welded joints is the presence of decarburized and carbide diffusion interlayers, which intensively increase in width during long-term high-temperature operation. The presence of wide interlayers negatively affects the mechanical properties of welded joints. Moreover, welded defects are difficult to diagnose in welded joints containing interlayers: due to the high structural heterogeneity, interlayers create structural noises that can hinder the detection of defects such as cracks, pores, or a lack of penetration. The AE method may become a complex decision for diagnosing dissimilar welded joints due to applicability to the testing of heterogenic materials with a complex microstructure. Specimens cut from dissimilar welded joints of austenitic steel to pearlitic steel were tested by tension to rupture, with parallel AE data registration. According to the research results, the characteristic features of the AE were revealed for specimens containing defects in the form of lack of penetration as well as for specimens with diffusion interlayers. The results obtained show that the AE method can be used to test both typical welding defects and diffusion interlayers in welded joints of steels of different structural classes.

 

Barat V., Marchenkov A., Ivanov V., Bardakov V., Elizarov S., Machikhin A. Empirical approach to defect detection probability by acoustic emission testing. Applied Sciences. 2021. Т. 11. № 20. С. 18. DOI: 10.3390/app11209429 (full text). https://www.mdpi.com/2076-3417/11/20/9429 (full text). eLibrary ID: 47514776

Abstract

Estimation of probability of defect detection (POD) is one of the most important problems in acoustic emission (AE) testing. It is caused by the influence of the material microstructure parameters on the diagnostic data, variability of noises, the ambiguous assessment of the materials emissivity, and other factors, which hamper modeling the AE data, as well as the a priori determination of the diagnostic parameters necessary for calculating POD. In this study, we propose an empirical approach based on the generalization of the experimental AE data acquired under mechanical testing of samples to a priori estimation of the AE signals emitted by the defect. We have studied the samples of common industrial steels 09G2S (similar to steel ANSI A 516-55) and 45 (similar to steel 1045) with fatigue cracks grown in laboratory conditions during cyclic testing. Empirical generalization of data using probabilistic models enables estimating the conditional probability of record emissivity and amplitudes of AE signals. This approach allows to eliminate the existing methodological gap and to build a comprehensive method for assessing the probability of fatigue cracks detection by the AE testing.

 

A. Yu. Poroykov, M. O. Sharikova, A. Yu. Marchenkov, V A Barat. Optical diagnostics of railway rail defects. J. Phys.: Conf. Ser. 2021. 2127 012044. https://iopscience.iop.org/article/10.1088/1742-6596/2127/1/012044 (full text). DOI: 10.1088/1742-6596/2127/1/012044. eLibrary ID: 48128683

Abstract

The safety of rail transport, including passenger traffic, largely depends on the timely diagnosis of the state of the rail infrastructure. To determine the state of metal structures, the method of acoustic emission (AE) is used. It is based on the registration of elastic mechanical vibrations arising in the material of the controlled object from a defect. The AE method is highly informative, but the interpretation of measurement results often causes difficulties, especially when studying complex structural elements. In this paper, it is proposed to use the digital image correlation (DIC) method to study the defects of railway rails using the acoustic emission method. Visualization of defects using the DIC method will make it possible to better interpret the results of inspection by the acoustic emission method and to establish the relationship between the size of defects and the parameters of AE pulses.

 

Matvienko Y.G., Vasil’ev I.E., Chernov D.V., Ivanov V.I., Elizarov S.V. Problems of locating acoustic emission sources. Russian Journal of Nondestructive Testing. 2021. Т. 57. № 9. С. 769-778. DOI: 10.1134/S1061830921090060. eLibrary ID: 47542918

Abstract

The accuracy of locating acoustic emission (AE) sources in the zones of stress raisers (central holes 5 mm in diameter) located a distance of 40 mm away from the receiving transducers has been assessed during rupture tests of flat specimens made of steel, an aluminum alloy, and a composite with overall dimensions of 550×50×4 mm. The dependence of the calculated propagation velocity of AE pulses on their amplitude and partial energy of various modes of Lamb waves has been studied. With the threshold method of signal recording, the error in locating AE sources when the distance between an AE source and the receiving AE transducer (AE) ΔL<0.1 m can exceed 10% of the base size (B) of the location area. For AE pulses with an amplitude of um<60 dB, the error level can reach 20–30% of the base size of the antenna array with a decrease in distance ΔL<0.05 m.

 

2020:

Vera Barat, Vladimir Bardakov, Denis Terentyev, Sergey Elizarov. Analytical Modeling of Acoustic Emission Signals in Thin-Walled Objects. Appl. Sci. 2020, 10(1), 279; DOI: 10.3390/app10010279 (full text). https://www.mdpi.com/2076-3417/10/1/279 (full text). eLibrary ID: 43236002

Abstract

For the effective detection of acoustic emission (AE) impulses against a noisy background, the correct assessment of AE parameters, and an increase in defect location accuracy during data processing are needed. For these goals, it is necessary to consider the waveform of the AE impulse. The results of numerous studies have shown that the waveforms of AE impulses mainly depend on the properties of the waveguide, the path along which the signal propagates from the source to the sensor. In this paper, the analytical method for modeling of AE signals is considered. This model allows one to obtain model signals that have the same spectrum and waveform as real signals. Based on the obtained results, the attenuation parameters of the AE waves for various characteristics of the waveguide are obtained and the probability of defect detection at various distances between the AE source and sensor utilized for evaluation.

 

Barat V.A., Fomin A.A., Zhgut D.A., Marchenkov A.Y. Advanced Method for Acoustic Emission Testing Data Analysis. International Journal of Scientific and Technology Research. 2020. Т. 9. № 2. С. 5489-5492. https://www.ijstr.org/final-print/feb2020/Advanced-Method-For-Acoustic-Emission-Testing-Data-Analysis.pdf (full text)

Abstract

The article deals with application of Data Mining techniques for the analysis of acoustic emission data. Association rules and decision trees application are considered for acoustic emission data structuring and classification.

 

Yelizarov S.V. A-Line family of autonomous systems for integrated monitoring of main gas pipelines. In: Improvement of reliability of main gas pipelines subject to stress corrosion cracking. V International Scientific and Technical Seminar. December 16-18, 2020. Moscow, 2020. С. 39. Gazprom. eLibrary ID: 44589350 (full text)

Abstract

The current level of development of telecommunications technologies and NDT tools allows receiving and processing a large array of diagnostic data from various facilities in real time, including facilities operated in harsh weather conditions on remote areas. Our company offers a broad range of monitoring solutions, including autonomous systems for diagnostics and monitoring of main gas pipelines. The monitoring should be construed as a specially organized systematic monitoring of both the pipeline itself and related utility structures. This monitoring is carried out continuously using a broad range of different types of sensors that record the characteristics of processes occurring in the material of structures and in the surrounding space. The monitoring system performs the following tasks: timely detection of defects in pipelines, their localization and tracking of the development of strain-stress state of pipelines and its monitoring in the areas of maximum stress concentration; monitoring of the efficiency of electrochemical protection of underground pipelines; acquisition and storage of data, the output of operational information to the control room, automation of data analysis and reduction of the role of the human factor in the evaluation of the results of the inspection, generation of an alarm about the upcoming abnormal situation and the need of unscheduled shutdown of pipelines.

 

2019:

Barat V., Bardakov V. Features of Noise Filtering During Acoustic Emission Testing. International Journal of Innovative Technology and Exploring Engineering. 2019. V. 9. № 1. С. 3977-3980. DOI: 10.35940/ijitee.A5067.119119 (full text). https://www.ijitee.org/portfolio-item/A5067119119/ (full text). eLibrary ID: 41819077

Abstract

This article discusses the problems of the acoustic emission method of non-destructive testing. An approach to filtering noise arising from monitoring of acoustic emission is considered. The filtering of acoustic noise is one of the key problems of the acoustic emission method, since the low noise immunity of the acoustic emission method prevents the expansion of its industrial application. The complexity of the filtering is explained by the fact that the waveform and spectrum of acoustic emission pulses change depending on the distance between the defect, which is the source of acoustic emission waves, and the sensor. In turn, the interference, as a rule, is non-stationary in nature and is determined by the type of technological process of the tested composition. This article discusses various types of noise processes, both stationary and non-stationary. The signal and noise parameters are compared, based on which recommendations are given for constructing algorithms for detecting acoustic emission pulses against a background of noise.

 

Barat V., Bardakov V., Marchenkov A. Empirical Modelling of Acoustic Emission Impulses. International Journal of Innovative Technology and Exploring Engineering. 2019. Т. 8. № 12. С. 3661-3664. DOI: 10.35940/ijitee.L3819.1081219 (full text). https://www.ijitee.org/portfolio-item/L38191081219/ (full text). eLibrary ID: 41714350

Abstract

Emission nondestructive testing method is very widespread diagnostic method based on phenomena of radiation of acoustic waves during the materials destruction. The main advantages of the method are sensitivity to the crack and possibility of remote testing when sensor installed far from the defect. The main drawback of the method is complexity of data processing. Acoustic emission signals are characterized by the variability of the shape and spectrum associated with the dispersive nature of the propagation of the signal along the waveguide. Uncertainty of the signal waveform and spectrum complicates the development of the data processing methods. The article proposes an empirical model of the acoustic emission impulse constructed using generalization of experimental data. The use of this model makes it possible to increase the efficiency of noise filtering by comparing the shape and spectrum of acoustic emission impulses and noise at various distances between the defect and the sensor.

 

Barat V., Marchenkov A., Elizarov S. Estimation of Fatigue Crack AE Emissivity Based on the Palmer-Heald Model. Applied Sciences (Switzerland). 2019. Т. 9. № 22. С. 4851. DOI: 10.3390/app9224851 (full text). https://www.mdpi.com/2076-3417/9/22/4851 (full text). eLibrary ID: 41822114

Abstract

This article is devoted to materials testing by the acoustic emission (AE) method, which is the analysis of models and diagnostic parameters to assess the probability of detection of a defect in steel structures. The paper proposes to evaluate the emissivity of the material quantitatively by the number and dynamics of the accumulation of acoustic emission impulses. Experimental studies were carried out on pearlitic structural steels, including the loading of samples with fatigue cracks. It was established that the number of AE impulses emitted during loading of an object with a fatigue crack is a random variable corresponding to the normal distribution law. The results show that an estimate of the number of AE impulses emitted during the loading of samples with fatigue cracks can be obtained by distributing the multiplicative parameter D of the Palmer-Heald model by taking into account the maximum value of the applied load.

 

Barat V.A., Marchenkov A.Y., Elizarov S.V., Bardakov V.V. Acoustic Emission Model of Fatigue Crack in Low-Carbon Steel. International Journal of Mechanical and Production Engineering Research and Development. 2019. Т. 9. № 6. С. 433-442. DOI: 10.24247/ijmperddec201937 (full text). http://www.tjprc.org/publishpapers/2-67-1572855846-37.IJMPERDDEC201937.pdf (full text). eLibrary ID: 41821571

Abstract

One of the problems of the acoustic emission (AE) testing method is the parametric uncertainty of defect models. In this work, an empirical model of a fatigue crack is considered, which allows establishing quantitative relations between the parameters of a fatigue crack and AE data. The ambiguity in the interpretation of AE data is explained by the inhomogeneous stress-strain state of the material.

 

Bardakov, V.V., Elizarov, S.V., Barat, V.A., Terentyev, D.A., Kharebov, V.G., Medvedev, K.A. (2021) Acoustic Emission Testing of Energy Field Objects. WCAE-5 Guangzhou, China, November 5-8, 2019. In: Shen, G., Zhang, J., Wu, Z. (eds) Advances in Acoustic Emission Technology. Springer Proceedings in Physics, vol 259. 2021, Springer, Singapore. DOI: 10.1007/978-981-15-9837-1

Abstract

This article presents the work carried out on the energy field objects of the thermal power plants (TPPs) by means of acoustic emission (AE) method. In total, 5 examples of AE method applications on TPP are presented in the article, such as pipelines testing during hydraulic pressure test, valve leak detection, inflow detection of vacuum equipment, testing of cooling tower support columns, testing of power transformer insulation.

 

Sergey Elizarov, Alexander Alyakritsky, Pavel Trofimov, Alexey Bugankov and Arkady Shimansky. The Overview of A-Line AE Systems. WCAE-5 Guangzhou, China, November 5-8, 2019 (unpublished)

Makhutov, N. A.; Vasil’iev, I. E.; Chernov, D. V.; Ivanov, V. I.; Elizarov, S. V. Influence of the Passband of Frequency Filters on the Parameters of Acoustic Emission Pulses. Russian Journal of Nondestructive Testing, 2019, 55, 3, pp. 173-180. DOI: 10.1134/S1061830919030082. eLibrary ID: 41631625

Abstract

To study the effect of the passband of a digital filter on the nature of the attenuation of the amplitude of an acoustic emission (AE) pulse and on the change in the group velocity of a wave packet in the near zone of up to 300 mm from the radiation source, studies were conducted on a multilayered polymer-composite-material (PCM) panel and an AMG-2 aluminum alloy plate with a thickness of 6 mm. In the course of the experiments, it has been established that narrowing the passband of the digital filter from 30–500 to 100–200 kHz can significantly affect the accuracy of the coordinate location of AE-event radiation sources situated near AE transducers, at a distance of less than 100 mm. As the passband of the digital filter narrows and the low- and high-frequency components of the spectrum are cut off, the wave front of the recorded pulse becomes more gently sloping, resulting in an increase in the difference of arrival times (DAT) of pulses to the AE transducers and in a decrease in the calculated group velocity of the wave packet. The error arising in this case is greater than the passband of the filter applied.

 

2018:

V.A. Barat, D.V. Chernov, S.V. Elizarov. Method for Assessing the Likelihood of Fatigue Crack Detecting. Proceedings of the 33rd Conference of the European Working Group on Acoustic Emission, Senlis, France, 12-14 September 2018 https://www.ndt.net/article/ewgae2018/papers/76.pdf (full text)

Abstract

An estimation of the probability of defect detection (POD) is an actual task of acoustic emission (AE)testing. Despite the fact that AE testing is the most sensitive method of NDT, the POD is difficult to estimate. The probability depends on a set of random factors also not directly related to the size of the defect. The probability of detecting defects is currently being studied by many researchers, but the proposed approaches are not yet applied in practice. In the frame of this work, the method allowing to estimate the probability of fatigue crack with help of AE testing method was developed. This method allows to calculate the probability of fatigue defect detection taking into account the following factors: the stage of defect growing, the distance between AE source and sensor and the noise level.

 

V. Barat, D.A. Terentyev, S. Elizarov. Statistical non-parametrical algorithm for Acoustic Emission impulses detection adapted on the basis of modal analysis approach. Proceedings of the 33rd Conference of the European Working Group on Acoustic Emission, Senlis, France, 12-14 September 2018 https://www.ndt.net/article/ewgae2018/papers/78.pdf (full text)

Abstract

This work is devoted to the study of a nonthreshold method for detecting acoustic emission impulses.As a method of impulse detection, a statistical ranking algorithm based on comparing the ranks of samples in two neighboring sliding windows is considered. To select the setting parameters of the algorithm and verify its reliability, the modal analysis method is used. The modal analysis is a mathematically exact method that leads to a closed integral equation for the elastic fields in the waveguide and which naturally includes the problem of the selectivity of the mode, offering an idea of the physics of waveguide behavior. The non-threshold algorithm developed in the framework of this paper was tested using 10000 model signals. The results of the research showed its high reliability and accuracy. A numerical experiment based on model signals showed that using the proposed nonparametric rank detection algorithm, in comparison with the threshold method, the location error has decreased by 1.5-2 times.

 

Bardakov V.V., Barat V.A., Sagaidak A.I., Elizarov S.V. Acoustic Emission Behaviour of Overreinforced Concrete Beams. International Journal of Civil Engineering and Technology. 2018. Т. 9. № 8. С. 1583-1594. https://iaeme.com/MasterAdmin/Journal_uploads/IJCIET/VOLUME_9_ISSUE_8/IJCIET_09_08_159.pdf (full text). eLibrary ID: 38613439

Abstract

The paper presents the results of the conducted experimental studies on three-point bend testing of over-reinforced concrete beams with incremental cyclic load, up to destruction, using the acoustic emission method. In total 3 RC beams differ from each other in reinforcement type, concrete composition and ultimate load were tested. Special attention is paid to the investigation of the relationship between destructive processes occurring during the testing of reinforced concrete beams and the evolution of acoustic emission data registered during the test. The analysis described in the article makes it possible, on the basis of acoustic emission data, recorded during the tests, to distinguish the stages corresponding to the different technical state of over-reinforced concrete structures.

 

Bardakov V.V., Sagaidak A.I., Elizarov S.V., Barat V.A. Acoustic Emission Behaviour of Reinforcement Concrete Beams Subjected to 3 Point Bending. Proceedings of the 33rd Conference of the European Working Group on Acoustic Emission, Senlis, France, 12-14 September 2018. Pp. 523-534. https://www.ndt.net/article/ewgae2018/papers/77.pdf (full text)

Abstract

The paper presents the results of the conducted experimental studies on three-point bend testing of reinforced concrete beams with incremental cyclic load, up to destruction, using the acoustic emission method. Special attention is paid to the investigation of the relationship between destructive processes occurring during the testing of reinforced concrete beams and the evolution of acoustic emission data registered during the test. The analysis described in the article makes it possible, on the basis of acoustic emission data, recorded during the tests, to distinguish the stages corresponding to the different engineering status of reinforced concrete structures.

 

Bardakov V.V., Sagaidak A.I., Elizarov S.V., Barat V.A. Test of bending reinforced concrete structures by means of acoustic emission method. Journal of Acoustic Emission. 2018. Т. 35. С. S390-S401. http://www.aewg.org/jae/JAE-Vol_35-EWGAE-33.pdf (full text)

Abstract

The paper presents the results of the conducted experimental studies on three-point bend testing of reinforced concrete beams with incremental cyclic load, up to destruction, using the acoustic emission method. Special attention is paid to the investigation of the relationship between destructive processes occurring during the testing of reinforced concrete beams and the evolution of acoustic emission data registered during the test. The analysis described in the article makes it possible, on the basis of acoustic emission data, recorded during the tests, to distinguish the stages corresponding to the different engineering status of reinforced concrete structures.

 

Elizarov S.V., Barat V.A., Terentyev D.A., Kostenko P.P., Bardakov V.V., Alyakritsky A.L., Koltsov V.G., Trofimov P.N. Acoustic emission monitoring of industrial facilities under static and cyclic loading. Applied Sciences (Switzerland). 2018. Т. 8. № 8. С. 1228. DOI: 10.3390/app8081228 (full text). https://www.mdpi.com/2076-3417/8/8/1228 (full text). eLibrary ID: 35732329

Abstract

Acoustic emission (AE) testing is traditionally carried out on non-operating objects. Such requirement is associated both with the Kaiser effect, leading to the necessity for exceeding the test load above the working one and with a high level of noise during object operation. However, AE testing could be performed under operating conditions, if the AE data acquisition period is increased and a specialized method is developed, which should take account of the effect of various noise, features of the object loading under operating conditions, the effect of damaging factors and possible destruction mechanisms. This paper investigates the possibility to carry out structural health monitoring (SHM) of hydrotreaters, highway bridges, high-temperature pipelines, gas adsorbers, roller bearings of rotary kilns and draglines on the basis of AE method. Architecture of SHM-system and specific data analysis procedures are proposed.

 

Matuynin V.M., Barat V.A., Marchenkov A.Y., Chernov D.V., Elizarov S.V. Determination of the Residual Life of Steel Specimens According to Acoustic Emission Data with an Artificial Neural Network. International Journal of Mechanical Engineering and Technology. 2018. Т. 9. № 9. С. 1039-1047. https://iaeme.com/MasterAdmin/Journal_uploads/IJMET/VOLUME_9_ISSUE_9/IJMET_09_09_113.pdf (full text). eLibrary ID: 38629976

Abstract

In this paper, we consider one possible approach to solving the residual life prediction problem, based on the use of the acoustic emission (AE) method. With the development fatigue cracks generate AE waves. By the activity and energy of AE, it is possible to determine the stage of development of the fatigue defect and estimate the residual life. The object of the study in this paper was steel specimens, made of low-carbon alloyed steel. Specimens were subjected to cyclic loading up to failure, during the growth of fatigue cracks, AE signals were recorded. The parameters of the acoustic signals were used as informative signs for determining the state of the loaded object. An artificial neural network was used as a prognostic model.

 

Sagaydak A., Zimnukhov D., Krylov S., Konstantin S., Bardakov V. Adhesion Testing Between Concrete and Reinforcement by Acoustic Emission Method. 2nd International Workshop on Durability and Sustainability of Concrete Structures, DSCS 2018. Moscow, June 5-8, 2018. SP-326: American Concrete Institute, ACI Special Publication. 2018, V. 326, pp. 109.1-109.10. eLibrary ID: 38624903

Vasilev I.E., Matvienko Yu.G., Elizarov S.V., Chernov D.V. Method of acoustic-emission monitoring of degradation of material structure and predicting residual product strength. Russian patent №2690200 (2019). eLibrary ID: 39389050

Abstract

Field: physics. Substance: use: to monitor degree of degradation of material structure and to predict residual strength of product using acoustic emission diagnostics. Summary of invention consists in the fact that in process of acoustic-emission monitoring of article during breaking of registered acoustic-emission pulses into clusters of lower, average and upper energy level by value of relative energy is calculated not only accumulation of weight content of localized pulses, reflecting micro, meso and macro-structural processes of material destruction, but also the number of recorded location pulses per unit time (recording frequency) in clusters H, C, B, which are used together with weight parameters to assess degree of degradation of structure of material and forecast of residual strength and loss of bearing capacity by article. Effect: possibility of improving reliability and accuracy of assessment of degree of degradation of structure of article material and forecast of its residual strength without involving other methods of technical diagnostics and nondestructive testing.

 

Matvienko, Yu. G.; Vasil’ev, I. E.; Chernov, D. V.; Elizarov, S. V. Criterion Parameters for Assessing Degradation of Composite Materials by Acoustic Emission Testing. Russian Journal of Nondestructive Testing, 2018, 54, 12, pp. 811-819. DOI: 10.1134/S1061830918120070. eLibrary ID: 38702905

Abstract

A concept of monitoring the degree of degradation in the multilayered structure of polymer composite package has been developed at the laboratory for modeling damage and failure of machines at Mechanical Engineering Research Institute, RAS. The concept is intended for real-time acousticemission testing of products and employs new criterion parameters that reflect the percentage of location pulses in energy clusters characterizing the processes of destruction of material structure at the micro-, meso-, and macro-scale levels. The developed procedure, algorithm, and software for monitoring the process of degradation in the multilayered structure of polymer composite material package and predicting the residual strength of the product have been successfully tried in static tensile bench tests with a structurally similar sample of aircraft panel containing a honeycomb polymer filler.

 

Chernov, D. V.; Matyunin, V. M.; Barat, V. A.; Marchenkov, A. Yu.; Elizarov, S. V. Investigation of Acoustic Emission in Low-Carbon Steels during Development of Fatigue Cracks. Russian Journal of Nondestructive Testing , 2018, 54, 9, pp. 638-647. DOI: 10.1134/S1061830918090024. eLibrary ID: 38647792

Abstract

AE control results for cyclic tests of metal samples with a notch are presented. The main stages of the fatigue crack development and standard AE parameters are matched. A criterial plane which allows to separate clusters corresponding to the stages of stable and avalanche-like defect growth has been constructed. It is shown that the boundaries of clusters remain unchanged irrespectively to the differences in the kinetics of damage development.

 

2017:

Vera Barat, Peter Kostenko, Vladimir Bardakov, and Denis Terentyev. Acoustic Signals Recognition by Convolutional Neural Network. International Journal of Applied Engineering Research ISSN 0973-4562 Volume 12, Number 12 (2017) pp. 3461-3469. https://ripublication.com/ijaer17/ijaerv12n12_67.pdf (full text). eLibrary ID: 31066184

Abstract

Acoustic emission is non-destructive method which is widely and successfully used to assess the technical condition of industrial facilities. It is challenging to divide useful signals and a noise in the flow of acoustic emission data. In this paper we describe the application of convolutional neural networks to classify acoustic emission signals by their time frequency structures. Convolutional neural network was learned to classify acoustic emission signals with 95% accuracy. Acoustic signal recognition by convolutional neural networks can greatly simplify the data processing.

 

S. Elizarov, V. Bardakov, A. Shimanskiy, A. Alyakritskiy, D. Terentyev, V. Barat, A. Gogin, and V. Koltsov. UNISCOPE: Instrument Integrating NDT Methods. Springer Proceedings in Physics. Volume 218. Advances in Acoustic Emission Technology. Proceedings of the World Conference on Acoustic Emission-2017, pp. 65-74. DOI: 10.1007/978-3-030-12111-2_7. eLibrary ID: 41689952

Abstract

This article describes the use of the multifunction device UNISCOPE. Tightness test of shutoff and control valves, evaluation of the integral thickness of test object, and concrete strength forecasting and monitoring of the movement of pipeline pig are the main topics described in the paper.

 

Sergey Elizarov, Vladimir Bardakov, Denis Terentyev, Vera Barat and Dmitry Chernov. AE Testing of Equipment on Operating Mode. Approaches and Results. World Conference on Acoustic Emission (WCAE-2017, Xi'an, China, October 10–13, 2017) (unpublished)

Abstract

The possibility of organizing a continuous monitoring AE without decommissioning of the following objects is shown: a walking excavator of the dragline type, a high-temperature process pipeline, and a 7-span motor bridge across the river. For each of the objects, the optimal operating frequency range, the threshold level and the distance between the sensors were determined, and a data analysis technique was developed that makes it possible to identify useful signals against a background of high noise. When testing the walking excavator AE, two defects were found that turned out to be 20 and 30 mm cracks, while monitoring the high-temperature process pipeline - flow through the flanges.

 

Barat V.A., Shimanskij A.G. Method of non-threshold automatic intellectual registration of acoustic emission signals by non-destructive control device. Russian patent №2660403 (2018). eLibrary ID: 37376547

Abstract

Field: physics. Substance: using: for non-destructive testing with the acoustic emission method (AE). Summary of the invention is that registration of acoustic emission pulses is performed without the use of a threshold limitation in the estimation of the parameters of the pulses of acoustic emission and noise in time intervals of a certain duration, the acoustic emission pulses are recorded on the basis of a combined criterion if one of the two statistical hypotheses is satisfied - the hypothesis that the sixth-order moment is zero and the hypothesis of the difference in the dispersion of acoustic emission signal samples calculated in neighbouring time windows, the time of the onset of the acoustic emission pulse is determined within the allocated time interval by the cumulative sum method. Effect: technical result: simplification of the procedure for conducting AE control through automatic non-threshold data recording, an increase in the sensitivity of the AE method due to the recording of pulses with an amplitude on the order of the noise level, as well as an increase in the accuracy of the AE sources coordinates determination by determination of the AE pulse beginning time.

 

Bardakov, V. V.; Sagaidak, A. I. Forecasting the strength of concrete during its hardening by the acoustic-emission method. Russian Journal of Nondestructive Testing, 2017. V. 53, pp. 436-443. DOI: 10.1134/S106183091706002X. eLibrary ID: 31100657

Abstract

Concrete structure formation has been studied by the acoustic-emission method. Using the results of the experimental research, a relationship has been revealed between the acoustic-emission data registered during the first 24 hours of hardening of a concrete composition and its strength at the age of 28 days. Informative parameters of acoustic-emission data have been determined that correlate with the strength of the concrete composition at the age of 28 days.

 

Vasilev I.E., Matvienko Yu.G., Elizarov S.V., Chernov D.V. Method for monitoring degradation of material structure and determining residual strength of article. Russian patent No. 2649081 (2018). eLibrary ID: 38150525

Abstract

Field: measurement technology. Substance: use to monitor the degree of degradation of a material structure and to determine an article residual strength. Core of the invention is performing acoustic-emission (AE) monitoring using location groups of active emission converters, preamplifiers and a system of collection-processing of registered arrays of active emission pulses, herewith in real time pulses of active emission are graded as per the relative energy level and the average emission frequency, the lower, the middle and the upper clusters are formed within the field of the specified parameters, and the percentage of pulses in each cluster is calculated reflecting micro-, meso-, and macrostructural fractures of the material, wherein as informative and stable acoustic emission parameters for the cluster separation of signals the relative pulse energy is used measured in decibels and corresponding to the number of emissions in units, as per which when compared with the results of testing the material for destruction the degree of degradation and the residual strength of the article in the zone of acoustic emission monitoring is determined, herewith the boundaries of the formed clusters are established as per the results of the preliminary testing the material of the article basing on the nature of the pulses radiation sources and the used signals discrimination threshold level. Effect: ensuring the possibility in the process of acoustic-emission diagnostics of the article to monitor the degree of degradation of the material structure and to determine the residual strength of the article in the AE monitoring zone without involving other methods of technical diagnostics and non-destructive testing.

 

Kachanov, V. K.; Sokolov, I. V.; Matyunin, V. M.; Barat, V. A.; Bardakov, V. V.; Marchenkov, A. Yu. Evaluation of the Fracture Toughness of Titanium Nitride Hardening Coatings According to Kinetic Indentation and Acoustic Emission Parameters. Measurement Techniques, 2017, 60, 7, pp. 706—710. DOI: 10.1007/s11018-017-1258-4. eLibrary ID: 31048648

Abstract

The possibility of usage of kinetic indentification method combined with acoustic emission for TiN-based hardening coatings crack resistance evaluation is revealed. Appropriate compliance between the moments of the first сrack appearance in the coating, the first notch on kinetic indentification curve registration and high-energetic acoustic emission impulse registration is established. The ability of much accurate and sound evaluation of critical indentation load causing the first ring crack appearance around the indent in the coating is shown.

 

2016:

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.

 

2015:

Medvedeva, M. L.; Ratanova, M. D.; Barat, V. A. Acoustic Emission in Monitoring Corrosion of Crude Distillation-Unit Equipment. Chemical and Petroleum Engineering, 2015, 51, 7-8, pp. 574-577. DOI: 10.1007/s10556-015-0089-x. eLibrary ID: 27028647

Abstract

The possibility of detecting a change in the corrosion mechanism of carbon steel by analyzing acoustic-emission (AE) signals was investigated. The change in the corrosion mechanism of steel 20 with a change of pH was modeled in citrate buffers at various pH values. The overall steel corrosion rate, polarization curves, corrosion products, and AE signals associated with steel dissolution were analyzed. It was shown that AE monitoring of the overall corrosion of carbon steel could not only estimate the extent of corrosion but also detect changes in the corrosion mechanism.

 

D. A. Terentiev. Zastosowanie metody emisji akustycznej (AE) w diagnostyce urządzeń technicznych. Rynek inwestycji, 2015-2016, №09-10, str. 80-81. https://rynekinwestycji.pl/wp-content/uploads/2015/12/RYNEK-INWESTYCJI_Wydanie-9-10_2015_2016.pdf (full text)

Abstract

Emisja akustyczna (AE) jest „promieniowaniem” fal akustycznych w miejscu wystąpienia deformacji plastycznej ciał stałych, rozwoju wad (pęknięć, mikropęknięć, rozwarstwień, korozji, kruchości wodorowej itp.), tarcia, wyciekania cieczy i gazów przez pęknięcia – nieszczelności.

 

Matvienko, Yu. G.; Vasil’ev, I. E.; Ivanov, V. I.; Elizarov, S. V. The acoustic-emission properties of oxide tensosensitive indicators and signal recognition during the formation of cracks in a brittle coating layer. Russian Journal of Nondestructive Testing, 2015, 51, 1, pp. 39-49. DOI: 10.1134/S1061830915010052. eLibray ID: 23994060

Abstract

The acoustic-emission properties of brittle oxide tensosensitive indicators (TS) coatings are considered, which are used not only for determining the fields of the highest principal stresses (strains) in a substrate but also, when combined with the acoustic-emission (AE) method, for diagnosing flaws at an early deformation stage in structures. AE pulses that are generated in a brittle layer of a TS indicator during formation of cracks are analyzed as a function of the oxide-film thickness and the substrate-deformation rate. Proceeding from the features of AE pulses that arise during the formation of cracks in the brittle layer of a TS indicator, an algorithm for recognizing signals according to the shape of a decaying wave is proposed.

 

Pokhabov Yu.P., Lepikhin A.M., Chernov D.V., Barat V.A., Moskvichev V.V. Method for determining suitability of high-pressure metal compound tanks. Russian patent №2650822 (2018). eLibrary ID: 41030422

Abstract

Field: technological processes. Substance: use: for non-destructive testing of high-pressure metal-composite tanks using acoustic-emission signals. Essence of the invention is the fact that in the process of loading the tanks by gradually increasing their internal pressure parameters of acoustic emission signals are measured and used to determine the level of accumulated damage, and when the critical parameters have been reached, a decision is taken on the suitability of the tank for operation, while the calibration of the reference tank is performed to a level of no more than 1.25 of the preset working pressure with continuous monitoring of acoustic emission wave fluxes in the composite material and corresponding internal pressures in the tank, narrow band and broadband acoustical emission signals, corresponding to the processes of destruction of the matrix and fibers of the composite material, are isolated, by calculating the mean square deviation of the amplitudes of narrowband and broadband acoustic emission signals, determining the criterial parameters, corresponding to the quantiles of the empirical distribution functions of the mean square deviations of the amplitudes of narrowband and broadband acoustic emission signals, whose level is chosen not less than the level of the standard deviation of the noise flux of acoustic emission signals and not higher than the median value of the distribution, the choice of the level of the discrimination threshold based on the criterial parameters so that the discrimination threshold would correspond to at least 75 % of the difference in the criterial parameters of broadband and narrowband acoustic emission signals, obtained at the stage of calibration tests, loading of each subsequent tank is performed until the criterion parameter reaches the discrimination threshold, and the decision on the level of tank qualification is made on the basis of comparison of internal pressures in a batch of tanks corresponding to the thresholds of discrimination. Effect: technical result: increasing the reliability of the determination of suitable high-pressure metal-composite tanks.

 

2014:

Sergey Elizarov, Vera Barat, Arkady Shimansky. Nonthreshold Acoustic Emission Data Registration Principles. Proceedings of the 31st Conference of the European Working Group on Acoustic Emission, Dresden, 03-05 September 2014 https://www.ndt.net/article/ewgae2014/papers/we3b4.pdf (full text)

Abstract

Traditional way of acoustic emission (AE) signals registration is a threshold method. AE impulse is registered when acoustic signal exceeds preset threshold, and impulse standard parameters (amplitude, arrival time, rise time, duration and others) are counted in on-line mode. Threshold method is simple and stable one, but has a set of drawbacks. First of all, threshold value is set by operator, thus it could be set incorrectly due to human factor. Secondly, AE - impulse arrival time is calculated as time of threshold crossing, this value differs from real one, what leads to imprecision in AE sources location. Thirdly, threshold method considers acoustic emission as an impulse process with stationary noise background, this model does not suit to continuous emission or non-stationary noise cases. Intelligent nonthreshold method, based on theory of signal detection, may be considered as alternative to threshold method for AE impulse detection. In this approach AE impulses are detected as fragments of continuous data flow, which has specific waveform and frequency characteristics. Method implementation involves usage of adaptive and matched filtering and change point detecting algorithms in on-line mode. Intelligent method allows to evaluate impulses arrival times and detect impulses with amplitudes below noise level with help of adaptive filtering. High time accuracy AE - impulses detecting provides precise AE - sources location and criteria estimation, which enhances AE - testing method validity. By means of digital signal processing impulse and continuous signal products are extracted. AE signal continuous component is analyzed separately. Continuous component analysis allows to identify leaks, technological noise and pre-destruction continuous emission. Currently, due to the high level of circuit technology development nonthreshold algorithm of AE data acquisition can be implemented in hardware.

 

Sergey Elizarov, Arkady Shimansky, Vera Barat. Intelligent Acoustic Emission System. Proceedings of the 31st Conference of the European Working Group on Acoustic Emission, Dresden, 03-05 September 2014 https://www.ndt.net/article/ewgae2014/papers/p4.pdf (full text)

Abstract

Acoustic emission (AE) - testing method has a set of standing out special features, distinguishing it from other testing methods. It's a passive control method with high defects-detecting sensitivity, that does not need scanning of object surface and provides remote object testing with defects location on distances from meters to hundreds of meters. AE - method drawbacks are: high acoustic noise level induced by work of testing equipment, complexity of defects parameters estimation, high labor intensity and requirements to qualification of personnel, performing AE - testing. Nowadays different schools of sciences perform investigations for further development of AE - testing method, its possibilities enhancing, accuracy improving and practical field enlargement. Current article presents intellectual AE - system principles, such a system has upgraded AE - testing process by means of automation and intellectualization of functions, commonly performed by operator. Intellectual AE - system has automation of next functions: sampling rate assignment for correct time and frequency resolution, adaptive filtering of AE - signals for their efficient detecting against technological equipment noise background, and automated data registration without setting of threshold, sceto and other parameters by operator. Data registration procedure uses non-threshold statistical method of AE - impulses extraction on the basis of acoustic stationary noise properties changing. By means of digital signal processing pulse and continuous signal products are extracted, continuous product allows to identify leaks, technological noise and pre-destruction continuous emission. Intelligent AE system can improve the accuracy and reliability of the AE testing. Precise detection of acoustic emission impulses improves the AE sources location result, and precise location provides the precise AE source evaluation. Automatic determination of the setting parameters allows us to reduce the human factor influence on the results of the AE testing.

 

Alexander Sagaidak, Vladimir Bardakov, Sergey Elizarov, Denis Terentyev. The Use of Acoustic Emission Method in the Modern Construction. Proceedings of the 31st Conference of the European Working Group on Acoustic Emission, Dresden, 03-05 September 2014 https://www.ndt.net/article/ewgae2014/papers/fr1a3.pdf (full text)

Abstract

The method of acoustic emission is a very effective NDT method, which is widely used in nuclear power, oil, gas and chemical industry, mining and health care. The method of acoustic emission is widely used and standardized in many countries. In the modern construction of the method of acoustic emission finds wide application in non-destructive testing and evaluating the condition of building structures. The goals of this report are review of the regulatory standards and perspective investigations on the application of the acoustic emission method in modern construction and present results of several scientific researches on this topic. The main provisions of the report will be presented in accordance with the following content: current state of standards and guidelines on acoustic emission in the construction field, comparative analysis and prospects; the results of research conducted by authors in the Research, Design and Technological Institute for Concrete and Reinforced Concrete named after Gvozdev and practical experience of application of the obtained results. Civil construction buildings form a class of the test objects, for which the estimates of the structural integrity by acoustic emission method can become a successful commercial application.

 

Vasil'ev I.E., Matvienko Ju.G., Ivanov V..I., Elizarov S.V. Method of identifying sources of acoustic emission signals arising from degradation of material, cracking and structural failure. Russian patent №2569078 (2015). eLibrary ID: 37459314

Abstract

Field: physics. Substance: method includes measuring maximum pulse amplitude, the number of emissions and the duration of signal pulses, after which acoustic emission signal sources are identified based on said measurements. Effect: high reliability of identifying acoustic emission signal sources.

 

D. A. Terentyev, Yu. S. Popkov. Determination of the parameters of the dispersion curves of Lamb waves with the use of the Hough transform of the spectrogram of an AE signal. Russian Journal of Nondestructive Testing. January 2014, Volume 50, Issue 1, pp 19-28. DOI: 10.1134/S1061830914010082. eLibrary ID: 21877427

Abstract

A method for the recognition of dispersion curves on the spectrogram of acoustic-emission signals has been developed based on the Hough transform. The method was successfully tested in an experiment using a Hsu-Nielsen source. It has been determined that the suggested method can determine the distance from the source of a signal, even when the signal arrives only at one acoustic emission transducer. This enables one to perform AE testing only with one-sided access to any dimensional object or when there is a sufficiently large distance between transducers, when an AE signal reaches only one of them.

 

2013:

V. Barat and A. Firsov. Empirical method for leakage detection and quantification. 2nd World Conference on Acoustic Emission (WCAE-2), Shanghai, 2013 (unpublished)

A.I. Sagaidak and S.V. Elizarov. Perspective Directions of Acoustic Emission Application in Construction. 2nd World Conference on Acoustic Emission (WCAE-2), Shanghai, 2013 (unpublished)

Terentyev D.A. Integral Thickness Measuring. Springer. Proceedings in Physics 158. Advances in Acoustic Emission Technology. Proceedings of the World Conference on Acoustic Emission–2013. Shanghai, 2013. ISBN: 978-1-4939-1239-1. Pp. 623-632

Abstract

The method of integral thickness measuring has been developed. It is realizable on the basis of standard AE systems and AE sensors. On the object at a distance of several meters or tens of meters apart two AE sensors are placed. They are used as a transmitter and a receiver of the acoustic signals. On the spectrogram of received signals the dispersion curves are extracted. The arithmetic mean thickness, the thickness dispersion, and the estimation of the minimum thickness can be calculated.

 

Terent'ev D.A. Method to monitor dynamics of variation of controlled object wall thickness. Russian patent №2540942 (2015). eLibrary ID: 37425725

Abstract

Field: measurement equipment. Substance: solution includes the method of monitoring of controlled object wall thickness variation dynamics, including placement of at least one acoustic converter on its surface at the available distance from each other for emission of Lamb waves, and at least one converter for their reception, emission of a pulse signal at the specified moment of time, calculation of dependence of spectral density of received signal capacity on time, selection of the Lamb wave and frequency, determination of difference between time of reception of the selected frequency component of the selected Lamb wave and time of signal emission, determination of the value of group speed of the selected frequency component of the selected Lamb wave by available value of the distance between converters and value of the difference between time of reception of the selected frequency component of the selected Lamb wave and the time of signal emission, determination of the value of wall thickness by the produced value of the group speed selected by the value of frequency and reference dependence of the group speed of the selected Lamb wave on the product of wall thickness and frequency. The minimum value of wall thickness is established by produced arithmetic mean value of wall thickness and dispersion of object wall thickness values, besides, the arithmetic mean value of the wall is determined with selection of the symmetrical Lamb wave of zero order and at least one frequency, at which the reference dependence of the inverse value of the group speed of the symmetrical Lamb wave of zero order on the product of wall thickness and frequency is close to linear, and dispersion of wall thickness values is determined with selection of the antisymmetric Lamb wave of zero order and frequency, at which the reference dependence of the inverse value of the group speed of the antisymmetric Lamb wave of zero order on the product of wall thickness and frequency is substantially non-linear. Effect: reduced labour intensiveness, simplification and acceleration of wall thickness monitoring in objects of large area, elimination of necessity to obtain physical access to the entire surface of the object, subject to thickness monitoring, provision of the possibility to monitor thickness with available variations of thickness values, provision of the possibility to determine arithmetic mean and minimum values of thickness in a section between two acoustic converters installed on the object in random points, without prior measurement of thickness in the same points.

 

2012:

Vera Barat, Sergey Elizarov, Irina Bolokhova and Evgeniy Bolokhov. Application of ICI Principle for AE Data Processing. Journal of Acoustic Emission, 30, 2012, pp. 124-136 https://www.ndt.net/article/jae/papers/30-124.pdf (full text)

Abstract

During AE data processing, it is often necessary to determine the change points of parameters. The most important problems are arrival time detection and AE data segmentation. The first-arrival time of acoustic emission (AE) signal is very important parameter, which is used for event location and identification. At present there are many advanced arrival time determination methods, which significantly increase accuracy of estimation in comparison with traditional threshold crossing method. However, advanced methods have several disadvantages connected with algorithm parameters selection. Arrival time estimation algorithms are based on a calculation of several statistical parameters within a sliding time window. The time-window length is often chosen empirically by the operator. When criteria for window length selection are undefined an incorrect length selection is possible, as well as incorrect AE signal arrival time definition. This paper describes the method based on intersection of confidence interval (ICI) principle. This method allows one to select time parameters optimally and in automatic mode. Application of ICI principle increases the accuracy and reliability of first-arrival time estimation. The problem of segmentation data arises in connection with the necessity to identify the data. Specifically the definition in the data stream of time intervals corresponding to different stages of the observed processes.

 

Vera Barat, Sergey Elizarov, Irina Kovalchuk, Evgeniy Bolokhov. Application of ICI Principle for the First-Arrival Time Correction. Proceedings of the 30th European Conference on Acoustic Emission Testing & 7th International Conference on Acoustic Emission EWGAE 30 / ICAE 7, Granada, 12-15 September 2012, pp. 506-515 https://www.ndt.net/article/ewgae2012/content/papers/44_Barat_Rev1.pdf (full text)

Abstract

The first-arrival time of acoustic emission (AE) signal is very important parameter, which is used for event location and identification. At present there are many advanced arrival time determination methods, which significantly increase accuracy of estimation in comparison with traditional threshold crossing method. However, advanced methods have several disadvantages connected with algorithm parameters selection. Arrival time estimation algorithms are based on a calculation of several statistical parameters within a sliding time window. The time-window length is often chosen empirically by the operator. When criteria for window length selection are undefined an incorrect length selection is possible, as well as incorrect AE signal arrival time definition. This paper describes the method based on intersection of confidence interval (ICI) principle. This method allows to select time parameters optimally and in automatically mode. Application of ICI principle results in increasing of accuracy and reliability of first-arrival time estimation.

 

Sergey V. Elizarov, Alexander L. Alyakritskiy, Vassily G. Koltsov , Vera A. Barat, Pavel N. Trofimov. Portable NDT Instrument “Uniscope”. Proceedings of the 30th European Conference on Acoustic Emission Testing & 7th International Conference on Acoustic Emission EWGAE 30 / ICAE 7, Granada, 12-15 September 2012, pp. 711-715 https://www.ndt.net/article/ewgae2012/content/papers/13_Elizarov_Rev3.pdf (full text)

Abstract

The multipurpose NDT device "Uniscope" is presented below. This instrument has two wide band analog inputs for the connection of different transducers and two universal digital inputs for external measurement units. In the basic configuration "Uniscope" is a full-function 2-channel AE-system. As an option, the instrument can be equipped with parametric measuring blocks to register temperature, pressure, stress values and etc., leak testing software, estimating the amount of leakage, and vibration analysis elements. Such universality is reached through using various external measuring units to be connected to the common computing device, provided with generic software with the modern friendly interface. The instrument is made as a portable single-unit construct, with an operating keyboard, placed on the front face, and color LCD-display to visualize data. "Uniscope" has long operating time from two built-in rechargeable batteries. Storage of large bulk of data is available on readily accessible information media. The environmental protection and extended temperature range let to use "Uniscope" under difficult weather conditions.

 

Alexander Sagaidak, Sergey Elizarov, Nina Reshetilova. Experience in application of acoustic emission method for estimation of building construction condition. Proceedings of the 30th European Conference on Acoustic Emission Testing & 7th International Conference on Acoustic Emission EWGAE 30 / ICAE 7, Granada, 12-15 September 2012, pp. 679-685 https://www.ndt.net/article/ewgae2012/content/papers/45_Sagaidak_Rev1.pdf (full text)

Abstract

In this paper the experience in practical application of the acoustic emission (AE) method for estimation of the crane trestle condition at the Sayano-Shushenskaya Hydroelectric Plant after an accident, and the perspectives of the AE method for estimation of the building construction condition have been considered. To estimate the crane trestle condition at the Sayano-Shushenskaya Hydro, cyclic loadings of massive reinforced concrete constructions of the crane trestle were used. The Kaiser effect was applied for estimating stresses operating in the construction. The technique for estimation of the building construction condition has been developed and approved, which allows for defining the occurrence of structural damage beforehand. Results of the studies conducted is useful in monitoring of the critical structures.

 

Denis Terentyev, Yuri Borodin. Use of Lamb Wave Dispersion Curve Extraction from AE Signal Spectrogram for Determination of Distance to AE Source. Proceedings of the 30th European Conference on Acoustic Emission Testing & 7th International Conference on Acoustic Emission EWGAE 30 / ICAE 7, Granada, 12-15 September 2012, pp. 217-221 https://www.ndt.net/article/ewgae2012/content/papers/43_Terentyev_Rev1.pdf (full text)

Abstract

Case of AE testing of gas pipeline is described. Owing to the large value of acoustic signal attenuation and the large distance between sensors, signals from AE sources arrived only to one of the nearest sensors. This made it impossible to carry out usual location of sources based on the arrival time differences. At the same time the Lamb wave dispersion curves were observed on a number of AE signal spectrograms. Therefore, the technique of Lamb mode dispersion curves extraction from AE signal spectrograms by using the Hough transform was applied. Application of the offered technique on these objects appeared successful. The sources co-ordinates were calculated, and then, with the use of the known attenuation coefficient the effective amplitudes of signals were calculated, that enables AE classification. Furthermore, the use of dispersion curves analysis allowed for determining an average value of the wall thickness between AE source and AE sensor.

 

2011:

Barat V. , Grishin D and Rostovtsev M. Detection of AE impulses against background friction noise. Proc. of the 1st World Conference on Acoustic Emission (WCAE), Beijing, 2011, pp. 147-152

Abstract

The noise similar in waveform to AE signals are of particular complexity for filtering. These are the noise generated by various mechanical reasons - impact, impact of foreign objects, and precipitations. Friction is the most sophisticated and irremovable reason of noise, it is very complex for filtering. Detection of AE impulses against friction noise is possible with help of advanced digital signal processing methods - adaptive nonthreshold segmentations and principle component analysis.

 

V. Barat, D. Grishin and M. Rostovtsev. Detection of AE Signals against Background Friction Noise. Journal of Acoustic Emission, 29, 2011, pp. 133-141. https://www.ndt.net/article/jae/papers/29-133.pdf (full text). http://www.aewg.org/jae/JAE-Vol_29-2011.pdf (full text)

Abstract

Noise similar in waveform to AE signals is of particular challenge for filtering. Such noise is generated by various mechanical reasons, impact, impact of foreign objects, and precipitations. Friction is the most sophisticated and irremovable source of noise, as it is complex for filtering. Detection of AE signals against friction noise is possible using advanced digital signal processing methods; non-threshold segmentations, adaptive filtering and principal component analysis. Effective noise filtering is achieved both in real time and in post-processing mode.

 

Elizarov S.V., Alyakritskiy A.L., Koltsov V.G., Barat V.A. and Rostovtsev M.Yu. The new portable NDT device "Uniscope". Proc. Of the 1st World Conference on Acoustic Emission (WCAE), Beijing, 2011, pp. 553-556

Abstract

The 20-years experience in design and application of AE systems has allowed the "INTERUNIS" company to produce a new multipurpose NDT instrument – ―UNISCOPE‖. This instrument has two wideband analog inputs for attaching traditional sensitive elements of piezosensitive converter type and two general-purpose inputs for attaching external recording units through digital interfaces. As a base version, ―UNISCOPE‖ is a two-channel instrument for recording AE-impulses, enabling the linear location of sources. Optionally, the instrument functional can be completed by devices for measuring the stress-and-strain state, leak detection and vibrometry.

 

Sagaydak A.I. and Elizarov S.V. New Possibilities of Acoustic Emission Method for Research of Adhesion Between Concrete and Steel Bars of Different Profile. Proc. Of the 1st World Conference on Acoustic Emission (WCAE), Beijing, 2011, pp. 464-469

Abstract

The study of different kinds of profiles of reinforcing bars coupling with the concrete are presented. The acoustic emission method were used to observe the process characteristics. Purpose of these tests was: to develop the methodology for estimation of the profile type influence to the strength distribution into concrete along the bar; to explore the informative content of the recorded AE parameters; to study the profile type influence onto concrete destruction according to the location map.

 

D.A. Terentyev, V.A. Barat and K.A. Bulygin. The Extraction Method for Dispersion Curves from Spectrograms using Hough Transform. – Journal of Acoustic Emission, 29, 2011, 232-242. https://www.ndt.net/article/jae/papers/29-232.pdf (full text). http://www.aewg.org/jae/JAE-Vol_29-2011.pdf (full text)

Abstract

A Hough transform-based method is developed for the extraction of dispersion curves from spectrograms. This method has been successfully tested using experimental data from both an acoustic emission (AE) signal simulator, and actual AE sources. The method determines the distance to the signal source with an accuracy from 1 to 10% even when the signal arrives only to one sensor.

 

Terentyev D.A., Barat V.A., Bulygin K.A., and Zhukov A. Method for Dispersion Curves Extraction from Spectrograms and its Applications. Proc. of the 1st World Conference on Acoustic Emission (WCAE), Beijing, 2011, pp. 135-140

Abstract

A modification of Hough transform is developed for dispersion curves extraction from spectrograms. The extraction efficiency was confirmed through laboratory experiments. The use of the method enables precise AE source location and also allows AE system to measure the average wall thickness between 2 sensors separated by 1-56m with an accuracy to within about 1%.

 

2010:

Barat V., Alyakritskiy A., Bukatin A., Elizarov S., Rostovtsev M., Terentyev D. Automated intelligent methods for acoustic emission testing data processing. – Proc.10th ECNDT, Moscow, 2010 https://www.ndt.net/article/ecndt2010/reports/1_07_16.pdf (full text)

Vera Barat, Yrij Borodin and Alexey Kuzmin. Intelligent AE signal filtering methods. Journal of Acoustic Emission, 28, 2010, pp. 109-119 https://www.ndt.net/article/jae/papers/28-109.pdf (full text). http://www.aewg.org/jae/JAE-Vol_28-2010.pdf (full text)

Abstract

One problem of the acoustic emission (AE) testing is a high level of noise affecting the diagnosis results. Electric noise, electromagnetic interference, background acoustic noise, and rubbing noise are far from the full list of noise present during measurements. With the high level of noise, the operator has to increase the recording threshold of the AE impulses through reducing the testing sensitivity at the risk of missing a dangerous defect. Lack of the data filtering can result in an incorrect location and erroneous definition of the danger level of AE source. To improve the noise immunity of the AE system, the data filtering algorithms are to be used and examined in this paper.

 

Vera Barat, Yrij Borodin and Alexey Kuzmin. Intelligent AE signal filtering methods. Proceedings of EWGAE 2010, Vienna, 8th to 10th September https://www.ndt.net/article/ewgae2010/papers/3_Barat.pdf (full text)

Abstract

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 present under 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. False determination of AE parameters can result in wrong location and false determination of the AE source danger level. To improve the noise immunity of the acoustic emission system, the data filtering algorithms are to be used.

 

Kharebov V.G. Application of AE Method in Nuclear Power Industry. Proc.10th ECNDT, Moscow, 2010 https://www.ndt.net/article/ecndt2010/reports/1_07_22.pdf (full text)

V.G. Kharebov. Integrated diagnostic monitoring of hazardous production facilities. Proc.10th ECNDT, Moscow, 2010 https://www.ndt.net/article/ecndt2010/reports/1_12_20.pdf (full text)

A.I. Sagaidak and S.V. Elizarov. Application of acoustic emission method for brickwork diagnostics. Proceedings of EWGAE 2010, Vienna, 8th to 10th September https://www.ndt.net/article/ewgae2010/papers/48_Sagaidak.pdf (full text)

Abstract

Acoustic emission (AE) method becomes more and more widespread in construction industry. Also it is necessary to develop and standardize new methods of non-destructive testing which enables evaluation tests for anchors fixed in brickwork. This paper describes practical application of the acoustic emission and cyclic loading method to evaluate load-carrying capacity of an anchor fixed in the brickwork.

 

2008:

V. A. Barat and A. L. Alyakritskiy. Automated Method for Statistical Processing of AE Testing Data. Journal of Acoustic Emission, 26, 2008, 132-141. https://www.ndt.net/article/jae/papers/26-132.pdf (full text). http://www.aewg.org/jae/JAE-Vol_26-2008.pdf (full text)

Abstract

Acoustic emission (AE) as a nondestructive testing method allows estimating the condition of sophisticated industrial objects, detecting defects at their initiation, and preventing development of such defects. The reliability of detection and the accuracy of determination of AE source location depend on the correct interpretation of the AE testing results. Testing procedures of different industrial equipment are intended for estimating condition of the objects on the basis of AE parameters, while the AE signals proper are not used in analysis as the primary diagnostic data. We have developed the statistical method of analysis to study the whole complex of measured data, both the AE parameters and signal waveforms. This method is based on the two-level clustering of data, such as AE signals from separate channels, and "groups of signals" formed on the basis of the primary clustering. The algorithm allows the determination of the quantity of AE sources, and estimates the degree of their danger without resorting to the preliminary location. The zonal location is carried out after the determination of AE sources. It avoids the so-called false locations, which considerably complicate the location map. On the basis of classification results, one can correct the AE signal arrival time, and such correction makes it possible to improve the accuracy of the AE source location. The characteristic property of the developed method is data processing in an automatic mode, with minimal operator intervention. In this case there is no need to employ a high-skilled operator. Since the AE signals themselves are used for analysis, the obtained results prove to be more reliable than those obtained when working with the AE parameters. The algorithm built on the developed method has been successfully applied for processing data obtained as a result of laboratory research of the corrosion development, for studying reinforced concrete structures, and also as an additional instrument for processing data of the industrial AE testing.

 

V. A. Barat and A. L. Alyakritskiy. Automated method for statistical processing of AE testing data. Proc. 28th EWGAE Conf. Cracow. 2008, pp. 76-81. https://www.ndt.net/article/ewgae2008/papers/76.pdf (full text)

Abstract

Acoustic emission (AE) as a nondestructive testing method allows estimating the condition of sophisticated industrial objects, detecting defects at their initiation, and preventing development of such defects. The reliability of detection and the accuracy of determination of AE source location depend on the correct interpretation of the AE testing results. Testing procedures of different industrial equipment are intended for estimating condition of the objects on the basis of AE parameters, while the AE signals proper are not used in analysis as the primary diagnostic data. We have developed the statistical method of analysis to study the whole complex of measured data, both the AE parameters and signal waveforms. This method is based on the two-level clustering of data, such as AE signals from separate channels, and "groups of signals" formed on the basis of the primary clustering. The algorithm allows the determination of the quantity of AE sources, and estimates the degree of their danger without resorting to the preliminary location. The zonal location is carried out after the determination of AE sources. It avoids the so-called false locations, which considerably complicate the location map. On the basis of classification results, one can correct the AE signal arrival time, and such correction makes it possible to improve the accuracy of the AE source location. The characteristic property of the developed method is data processing in an automatic mode, with minimal operator intervention. In this case there is no need to employ a high-skilled operator. Since the AE signals themselves are used for analysis, the obtained results prove to be more reliable than those obtained when working with the AE parameters. The algorithm built on the developed method has been successfully applied for processing data obtained as a result of laboratory research of the corrosion development, for studying reinforced concrete structures, and also as an additional instrument for processing data of the industrial AE testing.

 

Sergey Elizarov, Аnton Bukatin, Мikhail Rostovtsev and Denis Terentyev. New Developments of Software for A-Line Family AE Systems. – Journal of Acoustic Emission, 26, 2008, 311-317. https://www.ndt.net/article/jae/papers/26-311.pdf (full text). http://www.aewg.org/jae/JAE-Vol_26-2008.pdf (full text)

Abstract

The universal A-Line software of Interunis is an integral part of acoustic emission (AE) systems and is designed for solving various problems of data processing and visualization, and for full-scale control of the system hardware component. Simultaneously with development of new generations of the A-Line AE systems the software has been improved, is based on the upto-date information technologies and programming methods, incorporating real AE applications experience of internal and external users of the A-Line family AE systems. This paper briefly describes the significant functional features of program features implemented recently; a method of approximate location of AE sources using a free-form sensor array on surfaces of thin-wall vessels, information statistical criterion for division of AE sources according to the type and method for evaluating the distance from a sensor to an estimated source on the basis of waveletanalysis of AE impulse taking into account the dispersion dependencies of group velocities of Lamb waves.

 

Sergey Elizarov, Аnton Bukatin, Мikhail Rostovtsev and Denis Terentyev. New developments of software for A-Line family AE systems. Proc. 28th EWGAE Conf. Cracow. 2008, pp. 316-321. https://www.ndt.net/article/ewgae2008/papers/316.pdf (full text)

Abstract

The universal A-Line software of Interunis is an integral part of acoustic emission (AE) systems and is designed for solving various problems of data processing and visualization, and for full-scale control of the system hardware component. Simultaneously with development of new generations of the A-Line AE systems the software has been improved, is based on the upto-date information technologies and programming methods, incorporating real AE applications experience of internal and external users of the A-Line family AE systems. This paper briefly describes the significant functional features of program features implemented recently; a method of approximate location of AE sources using a free-form sensor array on surfaces of thin-wall vessels, information statistical criterion for division of AE sources according to the type and method for evaluating the distance from a sensor to an estimated source on the basis of waveletanalysis of AE impulse taking into account the dispersion dependencies of group velocities of Lamb waves.

 

V.G. Kharebov, S.V. Elizarov, Yu.P. Borodin. AE development and prospects in Russia. 28th EWGAE Conf. Cracow. 2008 (unpublished)

Yu. S. Popkov, A. L. Alyakritskiy, E. Yu. Sorokin and D. A. Terentyev. AE method for determination of pitting corrosion depth and monitoring of defect propagation rate. Proc. 28th EWGAE Conf. Cracow. 2008, pp. 59-63 https://www.ndt.net/article/ewgae2008/papers/59.pdf (full text)

Abstract

At present in Russia the local corrosion failure of equipment is one of the most serious problems in industry. This results from the increased scope of workload in oil, gas, petrochemical and nuclear industries, from considerable aging of the equipment used in these industries, and with more rigid requirements for safe operation of the equipment. Implementation of acoustic emission (AE) monitoring systems is one of the ways for reducing the number of corrosion failures. In recent years, we have researched processes of local corrosion formation and propagation using the AE method. In this paper, works on pitting corrosion, the most frequently encountered type, are described. Experiments for the determination of corrosion pit depth and evaluation of its propagation on carbon steel specimens in 1% solution of sulfuric acid are presented. By processing the frequency spectra of AE signals, the ratio of high-frequency S0- and low-frequency A0-modes of Lamb waves is defined. This ratio and the pit penetration depth are correlated. The propagation rate of pitting is evaluated by changes in the number of signals detected per unit time with significant S0-mode of Lamb waves. For a 5-mm thick specimen, the frequency dividing two modes is 300 kHz. Dependence of the S0-energetic portion on the pitting corrosion development is found.

 

2007:

A.I. Sagaidak; S.V. Elizarov. Acoustic emission parameters correlated with fracture and deformation processes of concrete members. Construction and Building Materials, 2007. V. 21, pp. 477-482. DOI: 10.1016/j.conbuildmat.2006.04.004. eLibrary ID: 13556292

Abstract

Acoustic emission (AE) techniques is extensively applied to a variety fields in civil engineering. Currently a new generation of AE technique, which is able to register and process AE data in real-time, has appeared. Still, there exist some problems to correctly interpret these data and to completely understand the meaning of AE parameters. In order to solve these, several AE waveform and spectral parameters are investigated, based on an experimental study of concrete and reinforced concrete structures.

 

D.A. Terent’ev. Calculation of the shortest distances on the surfaces of tanks with bottoms in the form of an oblate ellipsoid of revolution. Russian Journal of Nondestructive Testing. 2007, Volume 43, Issue 1, pp 32-38. DOI: 10.1134/s1061830907010056. eLibrary ID: 13541321

Abstract

The problem of calculating the shortest distances between arbitrary points on the surfaces of tanks with cylindrical shells and bottoms in the form of an oblate ellipsoid of revolution has been solved with the use of Jacobi elliptical integrals. This problem is of great importance for acoustic-emission inspection.

 

Kharebov V.G., Aljakritskij A.L., Popkov Ju.S., Terent'ev D.A., Barat V.A., Sorokin E.Ju. Method for detection of local corrosion depth and tracking of its development. Russian patent №2379675 (2010). eLibrary ID: 37724998

Abstract

Field: measurement equipment. Substance: application: to detect depth of local corrosion and track its development. One or several converters of acoustic emission are installed onto controlled item, signal oscillogram is registered, differs by the fact that signal oscillogram is used to define share nso of symmetric So Lamb wave in signal and/or share of nA0 of antisymmetric Ao Lamb wave in signal, an share or shares produced as well as their ratio is used to understand depth and development of corrosion. Effect: improved information capacity of the corrosion defect detection process with the help of acoustic emission even by one signal produced at least by one converter of acoustic emission.

 

2006:

Alyakritskiy, A.; Elizarov, S.; Shaporev, V.; Trovimov, P. Overview of A-Line32D Series AE Systems, Produced by INTERUNIS, Ltd. In Proceedings of the 9th European Conference on NDT, Berlin, Germany, 25–29 September 2006 https://www.ndt.net/article/ecndt2006/doc/P227.pdf (full text)

Abstract

INTERUNIS, Ltd has worked in the field of Non-Destructive Testing since 1988, it develops and produces Acoustic Emission (AE) equipment and complex diagnostic monitoring systems. The 18-year experience has allowed to create A-Line AE systems family for AE data acquisition and processing that has become the INTERUNIS Trade Mark. A-Line 32D AE systems series innovations are overviewed in the paper. Several digital multi-channel AE systems are presented in new generation of A-Line 32D series. Along with A-Line 32D(PCI-8) AE system, which has a traditional design and an analog data transmission from preamplifier to the host computer over a coaxial cable, there is a new type of noise-immune A-Line 32D(DDM) AE systems – module systems for AE data acquisition and processing with a digital data transmission over a serial high-speed cable link or a wireless radio channel.

 

Alyakritskiy, A.; Elizarov, S.; Shaporev, V.; Trovimov, P. Overview of A-Line32D Series AE Systems, Produced by INTERUNIS, Ltd. 27th European Conference on Acoustic Emission Testing (EWGAE 2006), Cardiff, Wales, UK, September 20-22 2006 (unpublished)

Elizarov, Sergey V.; Alyakritsky, A.L.; Sagaidak, A.I. Acoustic Emission Parameters Dependence on the Destruction Process Characteristics into Concrete. Proceedings of the 27th European Conference on Acoustic Emission Testing (EWGAE 2006), Cardiff, Wales, UK, September 20-22 2006. Advanced Materials Research, 2006, v. 13-14, pp. 201-204. DOI: 10.4028/www.scientific.net/AMR.13-14.201. eLibrary ID: 23971550

Abstract

Acoustic emission (AE) techniques are extensively applied to a variety of fields including civil engineering. Now a new generation of AE techniques, which are able to register and process AE data in real-time, has appeared. Still, there exist some problems to correctly interpreting these data and to completely understand the meaning of AE parameters. In order to solve this, several AE waveform and spectral parameters are investigated, based on an experimental study of concrete and reinforced concrete structures.

 

Valeriy Shaporev, Vasily Zaitchuk.The Possibilities of Acoustic Emission Systems A-Line32D for Determination of Various Types of Defects. In Proceedings of the 9th European Conference on NDT, Berlin, Germany, 25–29 September 2006 https://www.ndt.net/article/ecndt2006/doc/P228.pdf (full text)

Abstract

An Acoustic Emission (AE) method of Non-destructive Testing (NDT) has widely adopted for diagnostics of various dangerous industrial objects for the latest years. The advantages of AE method are: detection and registration only of progressive defects, classification of defects by dangerous level, high sensitivity due to the growing defects, integrated ability to provide tests of whole object. The A-Line32D complex allows to find and to evaluate of danger degree of AE sources, caused by the following defects: in main metal and welded junctions (cracks, stratification, backfins, loss of metal due to a corrosion and mechanical origin, faulty fusion, fistulas, burn-through, craters, gas pore, slag inclusions), outflow of gas and liquid in vessels and pipelines, presence of active corrosion on a surface of metal, presence of an electrical breakdown in reactors, transformers and insulators of high-voltage lines, and much more. Now AE is used widely as main method of complex monitoring systems for dangerous objects.

 

Zhang H.-H., Yin X.-C., Liang N.G., Yu H.-Z., Li S.-Y., Wang Y.C., Yin C., Kukshenko V., Tomiline N., Elizarov S. Acoustic emission experiments of rock failure under load simulating the hypocenter condition. Pure and Applied Geophysics. 2006. Т. 163. № 11-12. С. 2389-2406. http://dspace.imech.ac.cn/bitstream/311007/16061/1/ja452.pdf (full text). eLibrary ID: 13529180

Abstract

A series of acoustic emission (AE) experiments of rock failure have been conducted under cyclic load in tri-axial stress tests. To simulate the hypocenter condition the specimens are loaded by the combined action of a constant stress, intended to simulate the tectonic loading, and a small sinusoidal disturbance stress, analogous to the Earth tide induced by the Sun and the Moon. Each acoustic emission signal can indicate the occurrence time, location and relative magnitude of the damage (micro-crack) in the specimen. The experimental results verified some precursors such as LURR (Load/Unload Response Ratio) and AER (Accelerating Energy Release) before macro-fracture of the samples. A new parameter, the correlation between the AE and the load, has been proposed to describe the loading history. On the eve of some strong earthquakes the correlation between the Benioff strain and the Coulomb failure stress (CFS) decreases, similar to the variation of LURR prior to strong earthquakes.

 

Aljakritskij A.L., Terent'ev D.A., Rostovtsev M.Ju. Method of defining geometrical coordinates of acoustic emission converters. Russian patent №2330277 (2008). eLibrary ID: 37656953

Abstract

Field: technical diagnostics; non-destructive check. Substance: method involves each of the object's acoustic emission (AU) converters emitting signals in turns, while the other AE converters are receiving these signals, and then an acoustic emission system defines unknown geometrical coordinates of AE converters on the basis of temporal parametres of the signals, each of which was emitted and/or received by a AE converter with at least one defined geometrical coordinate. Additionally calculation of unknown geometrical coordinates of AE converters uses temporal parametres of at least one signal emitted by an AE converter with all coordinates unknown, or received by an AE converter with all coordinates unknown. Effect: simpler and faster process of complexed object diagnostics and higher precision in defining coordinates.

 

2005:

Zhang H.-H., Yin X.-C., Liang N.-G., Yu H.-Z., Li S.-Y., Wang Y.C., Yin C., Kukshenko V., Tomiline N., Elizarov S. Experimental Study of Rock Failure Precursor Using Simulated Tide Stress - Load/Unload Response Ratio (LURR) And Accelerating Energy Release (AER). Yanshilixue Yu Gongcheng Xuebao. Том: 24. Номер: 17 Год: 2005 Pp.: 3172-3179. eLibrary ID: 13493988

Leshchenko V.V., Vinokurov V.I., Kharebov V.G. Method of testing reservoirs. Russian patent № 2265817 (2005). eLibrary ID: 37970975

Abstract

Field: non-distractive testing. Substance: method comprises using pickups of acoustic emission mounted on the outer surface of the reservoir wall and sealed pickup of acoustic emission that is mounted inside the reservoir to be tested. The submerged pickup of acoustic emission is secured directly to the bottom of the reservoir or is mounted at a distance from the bottom. Effect: enhanced precision.

 

2004:

Yu.P. Borodin; S.V. Elizarov; M.I. Efremov; V.G. Kharebov; N.Yu. Il'yushenkova. Acoustic Emission Monitoring of Cast Supports for Tank Wagons. Chemical and Petroleum Engineering, 2004, 40, 3-4, pp. 167-170. DOI: 10.1023/b:cape.0000033670.08052.15

Kuksenko Viktor, Elizarov Sergey, Tomilin Nikita, Yin Xiang-Chu. Influence of the Weak Mechanical Disturbances on the Fracture Nucleation Behavior According AE Measurement. DGZfP-Proceedings BB 90-CD. Proc. 26th European Conference on Acoustic Emission Testing (EWGAE-26), pp. 605-612. September 15-17, 2004 . Berlin, Germany https://www.ndt.net/article/ewgae2004/pdf/l61elizarov.pdf (full text)

Abstract

Two stages model of fracture process in heterogeneous materials is developed in A.F. Ioffe Physico-Technical Institute. The first stage that occupies the major period of time in the entire process is associated with the noncorrelated nucleation of microcracks. The second final stage is governed by formation and development of the fracture nucleation source. The fracture nucleation source behavior is under analysis during small-scale load-unload series

 

V.S. Kuksenko, V.N. Savelev, S.V. Elizarov and N.G. Tomilin. Diagnostics of Large-scale Equipment. Progress in Acoustic emission. The Japanese Society for NDI, 2004. Proceedings of IAES-17, November 9-12, 2004, Tokyo

Yin Xiang-Chu, Yu Huai-Zhong, Kukshenko Victor, Xu Zhao-Yong, Wu Zhishen, Li Min, Peng Keyin, Elizarov Surgey, Li Qi. Load-Unload Response Ratio (LURR), Accelerating Moment/Energy Release (AM/ER) and State Vector Saltation as Precursors to Failure of Rock Specimens. Pure appl. geophys. 161 (2004) 2405–2416. DOI: 10.1007/s00024-004-2572-8. http://dspace.imech.ac.cn/bitstream/311007/58475/1/JourArSuppl2016-194.pdf (full text). eLibrary ID: 13456834

Abstract

In order to verify some precursors such as LURR (Load/Unload Response Ratio) and AER (Accelerating Energy Release) before large earthquakes or macro-fracture in heterogeneous brittle media, four acoustic emission experiments involving large rock specimens under tri-axial stress, have been conducted. The specimens were loaded in two ways: monotonous or cycling. The experimental results confirm that LURR and AER are precursors of macro-fracture in brittle media. A new measure called the state vector has been proposed to describe the damage evolution of loaded rock specimens.

 

Yu H.Z., Yin X.C., Xia M.F., Xu Z.Y., Li M., Liang N.G., Peng K.Y., Victor K., Wu Z.S., Li Q., Surguei E. Experimental research on critical point hypothesis. Acta Seismologica Sinica. 2004. Т. 17. С. 129

Yu H.-Z., Yin X.-C., Zhang Y.-X., Xia M.-F., Ling N.-G., Li M., Xu Z.-Y., Peng K.-Y., Yan Y.-D., Kukshenko V., Wu Z., Qi L., Elizarov S. Experimental Study of State Vector. Earthquake. 2004. Т. 24. № 3. С. 1-7. eLibrary ID: 13453536

Sagaidak A.I., Elizarov, S.V. The relationship of acoustic-emission signals with the processes of deformation and fracture of building structures, Russian Journal of Nondestructive Testing, Vol. 40, 2004, No. 11, pp. 739-745. DOI: 10.1007/s11181-005-0052-6. eLibrary ID: 13466979

Abstract

The parameters and spectra of acoustic-emission signals that arise during the inspection of precast concrete structures are studied. The information content of these parameters is discussed in terms of flaws that develop in structures subjected to stresses.

 

Kharebov V.G., Trofimov P.N., Aljakritskij A.L., Elizarov S.V., Gogin A.V. Multichannel acoustic-emission system for testing industrial objects. Russian patent No.2267122 (2004). eLibrary ID: 37959264

Abstract

Field: investigating or analyzing materials. Substance: system comprises several measuring lines, each of which is defined by two or more channels interconnected in series for permitting retranslation and retrieving of data transmitted. Each channel consists of the converter of acoustical emission and device for recording and processing the signals of acoustical emission which is mounted directly on the object to be tested. The device for recording and processing the acoustical emission signals comprise power source, preamplifier, main amplifier, and unit for digital processing and transmitting data connected in series. Effect: expanded functional capabilities.