PSI - Issue 59

Sviatoslav Homon et al. / Procedia Structural Integrity 59 (2024) 545–550 Sviatoslav Homon et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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After analyzing the obtained test results (Fig. 1a, 1b, 1c) and Table 2, we conclude that with decreasing age, the strength and deformability of wood also decreases. The ultimate strength of wood decreases slightly from 60 to 40 years and significantly from 40 to 20 years. Therefore, the strength decreases in the interval from 60 to 20 years: for larch samples, it decreases by 35.4%; for pine samples, it decreases by 26.5%; for spruce samples, it decreases by 29.8% (Table 2). A decrease was also observed for critical deformations, particularly for larch wood at 19.8%, pine at 20.1%, and spruce at 28.7%. Final deformations also decreased for larch prisms by 19%, pine trees by 18%, and spruce by 24.7% (Table 2). The modulus of elasticity becomes smaller in the interval from 60 to 20 years: for larch samples, it decreased by 13.2%; for pine samples, it decreased by 13.1%; for spruce samples, it decreased by 17.0%. 4. Conclusions 1. Experimental studies of the effect of age on the strength and deformation characteristics of solid coniferous wood (larch, pine, spruce) were carried out in compression along the fibers under a hard load. Complete diagrams of «stress σс – deformations uc» from the beginning of loading to breaking (ascending and descending branches) were constructed. 2. The strength and deformation parameters slightly decrease from 60 to 40 years and significantly from 40 to 20 years. 3. The strength decreases in the interval from 60 to 20 years: for larch samples, it decreases by 35.4%; for pine samples, it decreases by 26.5%; for spruce samples, it decreases by 29.8%. 4. Critical relative deformations of conifers, determined experimentally with a decrease in the age of wood from 60 to 20 years, decrease, in particular, for larch wood by 19.8%, pine by 20.1%, and spruce by 28.7%. 5. Final deformations decreased for larch prisms by 19%, pine trees by 18%; and spruce by 24.7% 6. The initial modulus of elasticity decreases between 60 and 20 years: for larch, it decreased by 13.2%; for pine, it decreased by 13.1%; for spruce, it decreased by 17.0%. References 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 . Bojok, О. , Vintoniv, І. , 1992. Wood science with the basics of forest commodity science. Kyiv: Publishing by Scientific thought. Da Silva, A., Kyriakides, S., 2007. Compressive response and failure of balsa wood. International Journal of Solids and Structures 44 (25-26), 8685-8717. DBN B.2.6-161, 2017. Constructions of houses and buildings. Wooden constructions. Main provisions. Kyiv: Ukrarchbudinform. EN 380: 2008. Wood is constructional. General guidelines for static load test methods. Eurocode 5, 2004. Design of timber structures. Part 1.1. General rules and rules for buildings, 124. Donadon, B.F., Mascia, N.T., Vilela, R., Trautwein, L.M., 2020. Experimental investigation of Glued-Laminated wood beams with Vectran-FRP reinforcement. Engineering Structures 202, 109818. 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. Galicki, J., Czech, M., 2005. Tensile strength of softwood in LR orthotropy plane. Mechanics of Materials 37(6), 667 – 686. 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