20.500.12556/RUL-117870 Vpliv prirastnih značilnosti smrekovine in jelovine na mehanske lastnosti konstrukcijskega žaganega lesa diplomsko delo - visokošolski strokovni študij The impact of growth properties of spruce and fir on the mechanical properties of structural sawn timber Pri uporabi lesa za konstrukcijske namene, so bistvenega pomena njegove mehanske lastnosti. Ugotavljali smo vpliv gostote in prirastnih značilnosti smrekovine in jelovine na mehanske lastnosti konstrukcijskega žaganega lesa. Raziskavo smo izvajali na elementih dimenzij: 38 x 100 mm, 50 x 150 mm, 44 x 200 mm, 140 x 140 mm in dolžine 4000 mm. S štiri-točkovnim upogibnim preskusom smo elementom določili globalni modul elastičnosti (MOEg) in upogibno trdnost. Prirastne značilnosti smo ocenili vizualno, skladno s standardom SIST DIN 4074-1. Najvišji korelacijski koeficient pri združenih elementih v enotni vzorec, smo dobili med gostoto in MOEg (0,74) in med širino branike in MOEg, (-0,61). Najnižji korelacijski koeficient je bil med upogibno trdnostjo in oddaljenostjo obdelovanca od stržena (0,09) ter med upogibno trdnostjo in deležem kompresijskega lesa (-0,09). Enak korelacijski koeficient je bil tudi med deležem kompresijskega lesa in MOEg (-0,09). Med preučevanimi lastnostmi so za napovedovanje mehanskih lastnosti žaganega lesa najprimernejše gostota lesa in povprečna širina branike. The mechanical properties of wood are the most important when wood is used for constructional purposes. The influence of density and growth characteristics, comparing spruce and fir wood, on mechanical properties of constructions wood were studied. The elements with dimensions 38 x 100 mm, 50 x 150 mm, 44 x 200 mm, 140 x 140 mm with length 4000 mm were used in the study. Global modulus of elasticity (MOEg) and bending strength were determined at standard 4-point bending test. Growth characteristic were evaluated visually in accordance with SIST DIN 4074-1. We got the highest correlation coefficient when elements were placed in one statistical sample, e.g between wood density and MoEg (R = 0.74) and -0.61 between growth ring width and MOEg. The lowest correlation coefficient was achieved at relation between bending strength and distance of element from the pith (R = 0.09) and at correlation between compression wood share and MOEg of the tested elements (R = 0.09). Wood density and mean growth ring width were confirmed as the most reliable variables to predict mechanical properties of spruce and fir wood. konstrukcijski les smrekovina prirastne značilnosti lesa širina branike gostota trdnost construction wood spruce fir growth properties ring width density bending strength true false false [U. Zupan] Slovenski jezik Angleški jezik Diplomsko delo 2020-07-31 13:04:42 2020-07-31 13:04:47 2022-08-30 04:00:44 0000-00-00 00:00:00 2016 0 Ljubljana 2016 Ljubljana IX, 33 f., [30] f. pril. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 630*815:812.7 2669705 UNI_Zupan_Uros_2016.pdf UNI_Zupan_Uros_2016.pdf 1 CC3DE09EAA46415E0ED0AEBACC7DC308 d3fcf2709ccc40f602f6f4c7c1f505597226c09c224208deb81521ce707a94fa 48f0efb7-a1b9-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=131795 Biotehniška fakulteta 0 0 0