Utjecaj orijentacije drvnih stanica na tvrdoću drva

undergraduate thesis

• Title (english): Influence of wood cell orientation on hardness of wood
• Author: Josip Klanac
• Mentor: Vera Rede (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2021-02-25, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Osnovni cilj rada bio je istražiti utjecaj usmjerenosti strukture na tvrdoću drva obične smreke (Picea abies).
U teorijskom dijelu rada opisana je struktura drva, od makrostrukture do mikrostrukture te osnovna mehanička svojstva drva.
U eksperimentalnom dijelu prikazani su rezultati dobiveni mjerenjem tvrdoće po Brinellu u ovisnosti o usmjerenosti strukture. Površina na kojoj je izmjerena tvrdoća zakretala se od poprečnog (RT) do tangencijalnog (LT) presjeka u intervalima od po 15°. Za svaki kut napravljeno je deset mjerenja. Utvrđeno je da usmjerenost strukture ima veliki utjecaj na tvrdoću drva. Najviše vrijednosti tvrdoće dobivene su u poprečnom (50,0 HB), a najniže u tangencijalnom presjeku (26,1 HB). Rasipanja rezultata su relativno velika, a koeficijent varijacije za sve kutove ispitivanja kreće se u rasponu od 10,55 % do 19,85 %, što je manje od dopuštenog (20%).

Abstract (english)

The main aim of the study was to investigate the influence of the orientation of the structure on the hardness of spruce (Picea abies) wood.
The theoretical part of the paper describes the structure of wood, from macrostructure to microstructure and the basic mechanical properties of wood.
In the experimental part, the results obtained by measuring Brinell hardness as a function of the orientation of the structure are presented. The surface on which the hardness was measured rotated from the transverse (RT) to the tangential (LT) cross-section at 15° intervals. Ten measurements were made for each angle. The orientation of the structure was found to have a large influence on the hardness of the wood. The highest hardness values were obtained in the cross section (50.0 HB) and the lowest in the tangential cross section (26.1 HB). The scatter of the results is relatively large, and the coefficient of variation for all test angles ranges from 10.55 % to 19.85 %, which is less than allowed (20 %).

• Keywords: drvo; usmjerenost strukture; tvrdoća
• Keywords (english): wood; structure orientation; hardness
• Language: croatian
• URN:NBN: urn:nbn:hr:235:923745
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-02-23 18:55:03