Utjecaj orijentacije goda na tvrdoću drva obične smreke

undergraduate thesis

• Title (english): Annual ring orientation effect on hardness of European spruce
• Author: Antonio Gagulić
• Mentor: Vera Rede (mentor)
• Committee member: Branko Bauer (predsjednik povjerenstva)
• 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; General Mechanical Engineering (Construction)

Abstract

Osnovni zadatak ovog rada bio je istražiti kako promjena presjeka od radijalnog (LR) do tangencijalnog (LT) utječe na tvrdoću drva obične smreke (Picea abies) u longitudinalnom smjeru (L).
U teorijskom dijelu rada navedene su osnovne karakteristike građe te mehanička i fizikalna svojstva drva s osobitim naglaskom na ispitivanje tvrdoće Brinellovom metodom.
U eksperimentalnom dijelu rada utvrđeno je da se tvrdoća drva u longitudinalnom smjeru smanjuje s promjenom presjeka od radijalnog prema tangencijalnom. Najveća srednja vrijednost tvrdoće u iznosu od 59 HB izmjerena je u radijalnom presjeku, a najmanja vrijednost tvrdoće u iznosu od 38 HB izmjerena je u tangencijalnom presjeku. Ukupno smanjenje tvrdoće iznosi oko 36 %. Rasipanje rezultata pri mjerenju tvrdoće bilo je relativno veliko, ali je koeficijent varijacije manji od 7 % što je dosta manje od dopuštenog (20 %).

Abstract (english)

The main task of this paper was to examine how the change of section from radial (LR) to tangential (LT) affects the hardness of spruce wood (Picea abies) in the longitudinal direction (L).
The theoretical part of the paper gives the basic characteristics of structure as well as mechanical and physical properties of wood with emphasis on the Brinell hardness test.
In the experimental part of the paper, it was determined that the hardness of wood in the longitudinal direction decreases with the change of section from radial to tangential. The highest mean hardness value of 59 HB was measured in radial section and the lowest mean hardness value of 38 HB was measured in tangential section. Total reduction of hardness is about 36%. The scattering of the hardness measurement was relatively large, but the coefficient of variation was less than 7% which is much less than allowed (20%).

• Keywords: drvo; tvrdoća; orijentacija
• Keywords (english): wood; hardness; orientation
• Language: croatian
• URN:NBN: urn:nbn:hr:235:937651
• 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: 2021-02-18 13:40:04