List of publications in 2021, in which our employees participated:
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.