Vpliv velikosti preizkušencev na določanje mehanskih lastnosti lesa : diplomski projekt

Trop, Marko (author), Gorišek, Željko (mentor), Straže, Aleš (comentor), Gornik Bučar, Dominika (reviewer)

Raziskali smo vpliv velikosti preizkušanca in vlažnosti lesa na togostne lastnosti lesa. Izbrali smo les smreke in bukve ter izdelali preizkušance 6 različnih velikosti. V vsaki velikostni skupini smo izdelali po 5 preizkušancev. Preizkušance smo uravnovesili v 3 različnih klimatskih razmerah (%1 = 33 %, %2 = 65 %, %3 = 87 %). Uravnovešenim preizkušancem smo določili module elastičnosti s 3-točkovnim upogibnim testom po EN 408 in z dinamičnim vzbujanjem v vzdolžni in prečni smeri. Izkazalo se je, da je ujemanje med metodami dobro, z determinacijskim koeficientom med vrednostmi statičnega in dinamičnega modula elastičnosti večjim od 0,9. Gostota in vlažnost lesa sta pomembno vplivali na module elastičnosti smrekovine in bukovine, medtem ko vpliv velikosti preizkušancev ni bil značilen.

• Language: Slovenian
• Keywords: les, modul elastičnosti, togost lesa, dinamična metoda
• Work type: Diploma project paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: [M. Trop]
• Year: 2014
• Number of pages: IX, 28 f.
• PID: 20.500.12556/RUL-117618
• UDC: 630*812
• COBISS.SI-ID: 2275977
• Publication date in RUL: 17.07.2020

Secondary language

• Language: English
• Title: Influence of the specimen size on the determination of mechanical properties of wood

Abstract

The influence of the specimen size on testing the stiffness of wood was researched. The wood of Northern spruce and European beech was chosen and the specimens were produced in 6 different sizes. 5 specimens were produced for each size group. The specimens were equilibrated at 3 different climatic conditions (%1 = 33 %, %2 = 65 %, %3 = 87 %). The modulus of elasticity was determined for the equilibrated specimens using 3-point bending test according to EN 408, and dynamic excitation in longitudinal and transverse direction. It turned out that the correlation between the methods was good with the coefficient of determination between static and dynamic modulus of elasticity greater than 0.9. The density and the moisture content had a significant influence on the moduli of elasticity of spruce and beech wood, while impact of specimen size was not significant.

• Keywords: wood, modulus of elasticity, stiffness, dynamic method