Utjecaj usmjerenosti strukture na savojnu čvrstoću drva jele u longitudinalnom smjeru

undergraduate thesis

• Title (english): Effect of structural orientation on the bending strength in the longitudinal direction of fir wood
• Author: Emanuel Branimir Matić
• 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 ispitati utjecaj usmjerenosti strukture te savojnu čvrstoću drva jele (Abies alba) u longitudinalnom smjeru. Ispitivanje savojne čvrstoće provedeno metodom savijanja u tri točke. Savojna sila bila je okomita na longitudinalni smjer, a u odnosu na tangentu goda, pod kutem od 0°, 45° i 90°. Za svaki kut ispitano je po 33 uzorka.
Utvrđeno je da savojna čvrstoća ovisi o kutu između savojne sile i tangente na god.
Najveća vrijednost (91,9 N/mm2) dobivena je kod kuta od 0°, a najmanja (85,3 N/mm2) pod kutem od 45°. Vrijednost savojne čvrstoće kod kuta od 90° iznosila je 87,9 N/mm2.
Rasipanja rezultata pri ispitivanju savojne čvrstoće bila su relativno velika, ali je koeficijent varijacije (15,9 %) ipak bio ispod dopuštene vrijednosti (16 %).
Dobivene vrijednosti Weibullovog modula potvrđuju da se Weibullovom razdiobom mogu dobro opisati dobivene vrijednosti savojne čvrstoće.

Abstract (english)

The goal of this study was to examine the influence of the orientation of the structure and the flexural strength of fir wood (Abies alba) in the longitudinal direction. Flexural strength test was performed by the three-point bending method. The bending force was perpendicular to the longitudinal direction, and in relation to the tangent of the tree rings, at an angle of 0°, 45°, and 90°. 33 specimens were tested for each angle.
It was found that the bending strength depends on the angle between the bending force and the tangent per tree ring.
The highest value (91.9 N/mm2) was obtained at an angle of 0°, and the lowest (85.3 N/mm2) at an angle of 45°. The value of flexural strength at an angle of 90° was 87.9 N/mm2.
The variations in the bending strength test results were relatively large, but the coefficient of variation (15.9%) was still below the permissible value (16%).
The obtained values of the Weibull modulus confirm that the obtained values of flexural strength can be well described by the Weibull distribution.

• Keywords: savojna čvrstoća; usmjerenost; jela
• Keywords (english): flexural strength; orientation; fir tree
• Language: croatian
• URN:NBN: urn:nbn:hr:235:904757
• 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: 2022-02-24 07:23:46