20.500.12556/RUL-158760 Akustične lastnosti lepljenega lesa diplomsko delo - visokošolski strokovni študij Acoustical properties of glued laminated wood graduation thesis - higher professional studies Raziskali smo vpliv lepljenja lesa na njegove akustične lastnosti. Izbrali smo masivni smrekov les (Picea abies) in smrekov slojnat furnirni les (LVL) z debelino furnirja 0,8, 1,4 in 2,5 mm. LVL smo lepili s polivinilacetatnim (PVAc) in urea-formaldehidnim (UF) lepilom v preizkušance dimenzij 400 x 40 x 20 mm. Pri vzdolžnem in prečnem mehanskem vzbujanju smo izmerili frekvenčni odziv in dušenje zvoka ter določili togost ter kazalnike akustične kakovosti. Pri LVL sta število lepilnih slojev in vrsta lepila pozitivno vplivala na gostoto in togost materiala. Višjo togost smo dosegli pri LVL preizkušancih lepljenih s PVAc lepilom. Lepljenje pa je negativno vplivalo na hitrost zvoka v vzdolžni smeri preizkušancev in tudi na dušenje zvoka. Razlike med proučevanimi lepili v tem primeru nismo potrdili. Akustični koeficient K, učinkovitost akustične pretvorbe ACE in relativna učinkovitost akustične pretvorbe RACE je bila pri LVL bistveno nižja kot pri masivnem lesu. Ti parametri se niso značilno razlikovali glede na uporabljeno lepilo ali debelino furnirja. We investigated the effect of gluing of wood to its acoustic properties. We chose solid spruce wood (Picea abies) and spruce laminated veneer lumber (LVL) with thickness of veneer 0.8, 1.4 and 2.5 mm. LVL was glued with polyvinyl acetate (PVAc) and urea-formaldehyde (UF) adhesives in the test specimens of 400 x 40 x 20 mm. Longitudinal and transverse mechanical excitation of specimens was used, where the frequency response, sound damping, mechanical stiffness and acoustic quality indicators were determined. The number of veneer layers of LVL had a positive impact on the density and stiffness of the material. Higher stiffness was achieved in LVL specimens glued with PVAc adhesive. Bonding adversely affected the speed- and damping of sound in the longitudinal direction of the specimens. Differences between the studied adhesives in this case were not confirmed. Acoustic coefficient K, the acoustic conversion efficiency ACE and the relative acoustic conversion efficiency RACE were significantly lower at the LVL than that of solid wood. These parameters were not significantly different depending on the thickness of the used veneer. les slojnat furnirni les lepila akustične lastnosti wood laminated veneer lumber glues acoustical properties true false false B. Čamernik Slovenski jezik Angleški jezik Diplomsko delo 2024-06-20 10:00:14 2024-06-20 10:00:16 2024-07-04 03:39:30 0000-00-00 00:00:00 2016 0 Ljubljana 2016 Ljubljana VII, 28 f. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 630*812.12 2669961 UNI_Camernik_Bostjan_2016.pdf UNI_Camernik_Bostjan_2016.pdf 1 63E029D511AEA199F5380EDE0ABE1CC1 1294d4ce580e3ef6fe0a4a2a5fc353d71c6ed28acf5f13dba855ae7e5c703732 22090a5b-2edb-11ef-a73e-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=186479 Biotehniška fakulteta 0 0 0