Reološke lastnosti toplotno obdelanega lesa : diplomski projekt

Podbrežnik, Anja (author), Gorišek, Željko (mentor), Humar, Miha (reviewer)

Med neobdelanimi in toplotno obdelanimi preizkušanci bukovine (Fagus sylvatica L.) so bili pri treh ravnovesnih vlažnostih (uravnovešenih pri 33 %, 65 % in 87 % relativni zračni vlažnosti) iz statičnega preizkusa primerjalno ovrednoteni modul elastičnosti, upogibna trdost, deformacija do porušitve in vloženo delo, iz eksperimenta lezenja pa so bile določene elastična, zadržana elastična in plastična komponenta deformacije. Modul elastičnosti, upogibna trdnost, deformacija do porušitve in vloženo delo do loma so pri vseh treh vlažnostih manjši pri toplotno obdelanem lesu. Toplotna obdelava ima najmanjši vpliv na modul elastičnosti, največji pa na vloženo delo do loma. Toplotno obdelani preizkušanci imajo zelo majhno zadržano elastično in plastično komponento in se manj deformirajo, kar posledično pripelje do krhkega loma. Višja vlažnost ima na toplotno obdelan les manjši vpliv kot na neobdelan les, v obeh primerih pa deformacija z vlažnostjo raste.

• Language: Slovenian
• Keywords: les, toplotna obdelava, lezenje, bukev, Fagus sylvatica L.
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: [A. Podbrežnik]
• Year: 2012
• Number of pages: VII, 19 f.
• PID: 20.500.12556/RUL-684
• UDC: 630*82:532.135
• COBISS.SI-ID: 2048137
• Publication date in RUL: 11.07.2014

Secondary language

• Language: English
• Title: Rheological properties of heat-treated wood : B. Sc. thesis

Abstract

Between raw and heat treated specimens of beech (Fagus sylvatica L.) and three equal humidity balanced samples (with 33 %, 65 % and 87 % relative humidity) we performed comparative static tests, correlation test of evaluated elasticity modulus, bending hardness, deformation to fracture and evaluation of energy (force) needed for fracture. From creep experiment we defined elasticity deformation, restrained elasticity and plastic deformation of the component. Elasticity modulus, bending hardness, deformation to fracture and evaluation of energy (force) needed for fracture, are lower at heat treated samples at all three humidity levels. Heat treatment has smallest (minimal) effect of elasticity modulus, while it has greater effect on energy (force) needed for sample fracture. The heat treated specimens have very small restrained elasticity and plasticity components so they deform less, which leads to brittle fracture (crack). The higher humidity has smaller effect on heat treated wood, as it has effect on untreated wood, but in both cases deformation is increasing if humidity increases.

• Keywords: wood, heat treatment, creep, beech, Fagus sylvatica L.