Факультет архітектури, будівництва та енергетики
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Item type:Наукова стаття, Method of determination the initial elasticity modulus and timber deformation modulus under the influence of acid environment(2022) Homon, Sviatoslav; Vereshko, OlegThe technique of experimental researches of timber by axial compression along fibers by short-term loading for operation in various acid environments (hydrochloric, acetic and lactic acids) during displacements increase is developed. The results of researches of the initial elasticity modulus and the deformations modulus taking into account the factor of environment aggressiveness are given. It is found that the effect of acids on wood with different impregnation periods significantly reduces the initial elasticity modulus and deformation modulus and depends on the impregnation period.Item type:Наукова стаття, Theoretical analysis of the microrelief of typical machine-made surfaces by SEM photogrammetry(2024) Boyarska, Inna; Homon, Sviatoslav; Kulakovskyi, Leonid; Kulakovskyi, LeonidThe article analyzes digital elevation models (DEMs) of typical mechanically formed surfaces. The theoretical issues of 3D modeling of typical "ideal" surfaces obtained, for example, by artificially growing single crystals, forming regular microrelief of materials, etc. are considered. For this purpose, the most typical stepped, spherical, cylindrical, and cubic machined microrelief surfaces were selected. The algorithms for analytical photogrammetric and digital processing of SEM stereo images are presented and illustrated by relevant examples. The results of numerical integration for different surfaces are consistent with a typical "stepped" surface.Item type:Наукова стаття, Study of change strength and deformation properties of wood under the action of active acid environment(2023) Homon, Sviatoslav; Gomon, Petro; Gomon, Svyatoslav; Vereshko, Oleg; Boyarska, Inna; Uzhegova, OlgaExperimental studies of birch and pine wood by axial compression along the fibers under the action of active acidic environment with different soaking time were carried out. The complete deformation diagrams "stress σс - longitudinal deformation uс" of the examined wood species under such conditions were constructed. On the basis of the experiment, the actual values of ultimate strength, critical and residual (final) deformations of birch and pine wood under the action of an active acidic environment with different soaking time were determined. It was found that exposure to an acidic environment for 28 days of soaking significantly reduces the strength and increases the deformation characteristics of the studied wood samples compared to those at standard humidity. Under such conditions, the ultimate strength decreases by 42.4%; critical deformations increase by 18.5%, and residual deformations increase by 24.8%. It is also proved that the obtained mechanical characteristics depend on the soaking time with various aggressive environment and their concentration.Item type:Наукова стаття, Study of wood deformation indicators after exposure to acidic environments(2026) Vereshko, Oleg; Boyarska, Inna; Uzhegova, Olga; Shevchuk, Pavlo; Uzhehov, Serhii; Homon, Sviatoslav; Gomon, Svyatoslav; Gomon, PetroExperimental studies were conducted on the deformation indicators of structural birch and pine wood under the influence of various acidic environments with different impregnation times. The deformation parameters of all studied wood species were determined experimentally, in particular the critical uc,0,d,agr and residual deformations uc,fin,agr. It has been established that exposure to an acidic environment increases the deformation characteristics of structural timber.. Specifically, the relative critical deformations of the studied species increased within the range of 1.12 to 1.17 times after 28 days of impregnation compared to the samples tested at the standard moisture content of 12%, and within the range of 1.14 to 1.19 times after 180 days. Residual deformations increased 1.1 to 1.25 times after 28 days of impregnation, and after 180 days, they remained practically the same. Over the following five months, the strength and deformability characteristics changed insignificantly, they stabilized. This is explained by the fact that after 28 days of impregnation, the wood is almost completely saturated with moisture and subsequently hardly absorbs any more.