PSI - Issue 59

Victor Datsiuk et al. / Procedia Structural Integrity 59 (2024) 583–587 Victor Datsiuk et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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ranging from 12% to 15%, decrease compared to unused samples. For 25 years of service life at 12% moisture: the ultimate compressive strength decreased by 1.02-1.04 times and the modulus of elasticity slightly decreased within the range of 1.01-1.02 times. For 50 years of service life at 12% moisture: the ultimate compressive strength decreased by 1.04-1.06 times and the modulus of elasticity decreased in the range of 1.02-1.04 times. For 75 years of service life at 12% moisture: the ultimate compressive strength decreased by 1.06-1.09 times and the modulus of elasticity decreased in the range of 1.05-1.07 times. For 25 years of service life at 15% moisture: the ultimate compressive strength decreased by 1.03-1.06 times and the modulus of elasticity slightly decreased within the range of 1.02-1.05 times. For 50 years of service life at 15% moisture: the ultimate compressive strength decreased by 1.07-1.1 times and the modulus of elasticity decreased in the range of 1.05-1.08 times. For 75 years of service life at 15% moisture: the ultimate compressive strength decreased by 1.1-1.14 times and the modulus of elasticity decreased in the range of 1.09-1.12 times. Therefore, during prolonged use of pine wood, the strength parameters decrease. This is influenced by the temperature and humidity conditions, service life, loading regime, and damage during the operation. 4. Conclusions Experimental studies on pine wood were carried out after prolonged use within the range of 25-75 years, with moisture levels ranging from 12% to 15%, under compressive stress along the fibers. New experimental data regarding the changes in the fundamental strength properties of wood after prolonged use were obtained. Based on the results of the conducted experiment, it was established that the ultimate compressive strength and modulus of elasticity of pine wood, during a prolonged service life of 25-75 years with moisture levels ranging from 12% to 15%, decreased compared to unused samples. It was determined that the strength parameters after prolonged use are influenced by the temperature and humidity conditions, service life, loading regime, and damage during the operation. References Anshari, B., Guan, Z. W., Wang, Q. Y., 2017. Modelling of Glulam beams pre-stressed by compressed wood. Composite Structures 165, 160 – 170. ASTM D 143-14: 2014. Standart test methods for small clear samples of wood. Bosak, A., Matushkin, D., Dubovyk, V., Homon, S., Kulakovskyi, L., 2021. Determination of the concepts of building a solar power forecasting model. Scientific Horizons 24(10), 9-16 . Da Silva, A., Kyriakides, S., 2007. Compressive response and failure of balsa wood. International Journal of Solids and Structures 44 (25-26), 8685-8717. De Mets, T., Tilmans, A., 2020. Evaluation of the risk of decay of wooden beams embedded in internally insulated walls by long-term measurements. E3S Web of Conferences 172, article number 01002. DSTU EN 380: 2008. Wood is constructional. General guidelines for static load test methods. DSTU 3129: 2015. (2016). Wood. Methods of sampling and general requirements for physical and mechanical tests of small defect-free samples. Dvorkin, L., Bordiuzhenko, O., Zhitkovsky, V., Gomon, S., Homon, S. (2021). Mechanical properties and design of concrete with hybrid steel basalt fiber. E3S Web of Conferences 264, article number 02030. Gayda, S., Kiyko, O., 2020. The investigation of properties of blockboards made of post-consumer wood. Drewno 63(603), 77 – 102. Gomon, P., Gomon, S.S., Pavluk, A., Homon, S., Chapiuk, O., Melnyk, Yu., 2023. Innovative method for calculating deflections of wooden beams based on the moment-curvature graph. Procedia Structural Integrity 48, 195-200. Gomon, S.S., Gomon, P., Homon, S., Polishchuk, M., Dovbenko, T., Kulakovskyi, L., 2022. Improving the strength of bending elements of glued wood. Procedia Structural Integrity 36, 217-222. Gomon, S., Gomon, P., Korniychuck, O., Homon, S., Dovbenko, T., Kulakovskyi, L., Boyarska, I., 2022. Fundamentals of calculation of elements from solid and glued timber with repeated oblique transverse bending, taking into account the criterion of deformation. Acta Facultatis Xylologiae Zvolen 64(2), 37-47. Green, D.W., Kretschmann, D.E., 1992. Properties and grading of Southern Pine Woods. Forest Products Journal 47 (9), 78 – 85. Homon, S., Gomon, P., Gomon, S., Vereshko, O., Boyarska, I., Uzhegova, O., 2023. Study of change strength and deformation properties of wood under the action of active acid environment. Procedia Structural Integrity 48, 201-206. Homon, S., Litnitskyi, S., Gomon, P., Kulakovskyi, L., Kutsyna, I., 2023. Methods for determining the critical deformations of wood at various moisture. Scientific Horizons 26(1), 73-86. Imbirovych, N., Boyarska, I., Povstyanoy, O., Kurdzydlowski, K., Homon, S., Kulakovskyi, L., 2023 Modification of oxide coatings synthesized