Utjecaj usmjerenosti strukture na savojni modul elastičnosti drva jele u longitudinalnom smjeru

undergraduate thesis

• Title (english): Effect of structural orientation on the bending modulus of elasticity in the longitudinal direction of fir wood
• Author: Nikola Mrvelj
• Mentor: Vera Rede (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2022-03-02, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Cilj ovog rada je odrediti kako usmjerenost strukture drva jele (Abies alba) utječe na savojni modul elastičnosti u longitudinalnom smjeru. Ispitivanje savojnog modula elastičnosti provedeno je metodom savijanja u tri točke. Savojna sila bila je okomita na longitudinalni smjer, a u odnosu na tangentu goda djelovala je pod kutom od 0°, 45° i 90°. Za svaki kut ispitano je po 30 uzoraka.
Utvrđeno je da savojni modul elastičnosti u longitudinalnom smjeru ovisi o kutu između savojne sile i tangente na god.
Najveća srednja vrijednost savojnog modula od 6619,5 N/mm2 dobivena je kod kuta od 0°, a najmanja od 6067,2 N/mm2 pod kutom od 90°. Vrijednost savojnog modula elastičnosti kod kuta od 45° iznosila je 6113,4 N/mm2.
Rasipanja rezultata pri ispitivanju savojnog modula elastičnosti bila su relativno velika, ali je koeficijent varijacije bio ispod dopuštene vrijednosti od 20 %.
Pokazalo se da vrijednosti modula elastičnosti svih triju skupina slijede Weibullovu distribuciju.

Abstract (english)

The goal of this study was to determine how the orientation of the fir wood structure affects the flexural modulus of elasticity in the longitudinal direction. The flexural modulus of elasticity was tested by the three-point bending method. The flexural force was perpendicular to the longitudinal direction, and in relation to the tangent of the tree rings it acted at an angle of 0°, 45°, and 90°. For each angle were tested 30 samples.
It was found that the flexural modulus of elasticity in the longitudinal direction depends on the angle between the flexural force and the tangent per tree ring.
The highest mean value of the flexural modulus of 6619.5 N/mm2 was obtained at an angle of 0°, and the lowest of 6067.2 N/mm2 at an angle of 90°. The value of the flexural modulus of elasticity at an angle of 45° was 6113.4 N/mm2.
The dispersion of the results in the flexural modulus of elasticity test was relatively large, but the coefficient of variation was below the permissible value of 20%.
The values of the modulus of elasticity of all three groups were shown to follow the Weibull distribution.

• Keywords: savojni modul elastičnosti; drvo; usmjerenost; Weibullova distribucija
• Keywords (english): flexural modulus of elasticity; wood; orientation; Weibull distribution
• Language: croatian
• URN:NBN: urn:nbn:hr:235:442308
• 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: 2022-02-27 22:07:18