PSI - Issue 59

S.E. Donets et al. / Procedia Structural Integrity 59 (2024) 367–371 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

371 5

Formation of pitting cavities was observed on the inner surface of the pipe, such as on Fig. 4. Pitting caverns were of different size, some reaching 300 µm in depth. Microhardness testing was conducted in the vicinity area of a pitting cavern up to 70 µm from its edge, and also in the direction from the cavern‟s edge into the bulk . A decrease of microhardness was noticed, H 50 dropped from 2.3-2.4 GPa in the bulk of the material to 0.9-1.65 GPa. The reduced hardness of the damaged zone by corrosion is hypothetically attributed to loss of structural integrity, possible depletion of alloying elements and oxidation. 4. Conclusions The study used active thermographic analyses of a damaged and polluted water pipe within an experimental stand. The experimental setup involved cold water, which was progressively heated by the water heater. Thermograms were captured at stages of forced heating and subsequent cooling. The thermographic images provided insights into the temperature distribution along the pipe's surface to localize possible structural heterogeneities. Correlations between temperature fluctuations and thermal gradients were observed. The fractal maps of pipe‟s thermograms were calculated using Clarke‟s classic prism method. The findings reveal correlations and variations in the fractal dimensions of thermograms with possible thermal abnormalities. Acknowledgements The research presented in this article was financially supported by the Ukrainian government budget program «Government support for priority scientific research and scientific & technical (experimental) developments» (budget financial Code 6541230) and Simons Foundation Program: Presidential Discretionary-Ukraine Support Grants, Award No 1030287. References Bazaleev, M.І., Bryukhovetsky , V.V., Donets, S.E., Lytvynenko, V.V., Melyakova, О.А., Prokhorenko , E.M., Startsev, О.А., Shatov , V.V., 2023. Thermographic monitoring of nuclear power plant‟s spray ponds using infra -red data processing methods. Problems of Atomic Science and Technology 2(144), 148-152. Clarke, K.C., 1986. Computation of the fractal dimension of topographic surfaces using the triangular prism surface area method. Computers & Geosciences 12(5), 713-722. Donets, S.Ye., Lytvynenko, V.V., Startsev, O.A., Lonin, Yu.F., Ponomarev, A.G., Uvarov, V.T., 2023. Fractal analysis of fractograms of aluminum alloys irradiated with high current electron beam. Physics and Chemistry of Solid State 2(24), 249-255. Jachimowski A., 2017. Factors affecting water quality in a water supply network. Journal of Ecological Engineering 4(18), 110-117. Lam N., et. al, 2002. An evaluation of fractal methods for characterizing image complexity. Cartography and Geographic Information Science 1(29), 25-35. Latif J. et. al, 2022. Review on condition monitoring techniques for water pipelines. Measurement 193, 110895. Prohorenko, E.M., Klepikov, V.F., Lytvynenko, V.V., Bazaleyev, N.I., Magda, I.I., Prohorenko, T.G., Morozov, A.I., 2018. Application of IR radiometric diagnostic for control of vacuum connections of electrophysical installation. Problems of atomic science and technology 1(113), 212-217. Rathore, M.K., Kumar, M., Yadav, S., Mishra, A., 2014. Estimation of Fractal Dimension of Digital Images. International Journal of Engineering and Technical Research 2(9), 176-181. Shulyak S. et. al, 2021. Quality and safety of tap water in selected Ukrainian regions. Ukrainian Journal of Ecology 11(2), 274-283. Yu S., et. al, 2023. Laboratory validation of in-pipe pulsed thermography in the rapid assessment of external pipe wall thinning in buried metallic utilities. NDT & E International 135, 102791.