EXPERIMENTAL TESTING OF BIRCH WOOD
(2024) In TVSM-5000 VSMM01 20241Structural Mechanics
Department of Construction Sciences
- Abstract
- In this study the fracture energy has been evaluated for birch, which is a relatively common hardwood in Sweden. The Nordtest method has been used to extract the fracture energy through a 3-point bending setup. The fracture energy was studied in the weakest load orientation of the orthotropic wood, which was tensile loading perpendicular to its grain. The directional systems of radial-longitudinal (RL) and tangential-longitudinal (TL) were implemented and tested. The RL direction showcased a higher fracture energy than the TL direction, but it did at the same time display more unstable results. Two different shapes of fracture areas of the Nordtest specimens were tested, the rectangular shape as described in the standard, and a triangular... (More)
- In this study the fracture energy has been evaluated for birch, which is a relatively common hardwood in Sweden. The Nordtest method has been used to extract the fracture energy through a 3-point bending setup. The fracture energy was studied in the weakest load orientation of the orthotropic wood, which was tensile loading perpendicular to its grain. The directional systems of radial-longitudinal (RL) and tangential-longitudinal (TL) were implemented and tested. The RL direction showcased a higher fracture energy than the TL direction, but it did at the same time display more unstable results. Two different shapes of fracture areas of the Nordtest specimens were tested, the rectangular shape as described in the standard, and a triangular shape. The unstable results were mainly from RL loading with a rectangular fracture area. The specimens with a higher density showcased both tendencies for a higher load capacity and a higher fracture energy.
The experimentally obtained fracture energy was then implemented to calculate the splitting capacity of dowel-type joints, which were made from the same boards used for manufacturing the Nordtest specimens. The dowel joints were then created, tested and examined. The calculated and experimental data were then compared. The calculated capacity was higher than the experimental capacity, maybe due to an unknown/assumed shear modulus. Beams with a higher density and a prescribed minimum dowel edge distance (from Eurocode 5) also showcased a higher load carrying capacity. Beams with a shorter dowel-to-edge did not showcase a higher load capacity in relation to a higher density. The beams with a longer edge distance had a higher capacity, due to premature splitting being avoided, which was indicated by a larger dowel hole deformation. The beams with a smaller edge distance tended to have a smaller embedment deformation and a lower capacity. (Less) - Popular Abstract
- Raw material from the Swedish forests has been an important resource for the construction industry for many years. Spruce has always been a popular choice because of its great abundant population, but the Swedish forests consist of other species as well - one of which is birch, which potentially can be used for structural purposes! So, how competitive is birch?
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9171288
- author
- Esbjörnsson, Emma LU and Svensson, Johan LU
- supervisor
- organization
- alternative title
- Experimentellt testande av björk
- course
- VSMM01 20241
- year
- 2024
- type
- H3 - Professional qualifications (4 Years - )
- subject
- keywords
- Fracture energy, birch, birch wood, Nordtest method, 3 point loading, three point loading, beam, beams, wood, MTS, björk, brottenergi
- publication/series
- TVSM-5000
- report number
- TVSM-5275
- ISSN
- 0281-6679
- language
- English
- id
- 9171288
- alternative location
- https://www.byggmek.lth.se/english/publications-old/tvsm-5000-present-2014/
- date added to LUP
- 2024-08-09 10:09:21
- date last changed
- 2024-08-09 14:50:51
@misc{9171288,
abstract = {{In this study the fracture energy has been evaluated for birch, which is a relatively common hardwood in Sweden. The Nordtest method has been used to extract the fracture energy through a 3-point bending setup. The fracture energy was studied in the weakest load orientation of the orthotropic wood, which was tensile loading perpendicular to its grain. The directional systems of radial-longitudinal (RL) and tangential-longitudinal (TL) were implemented and tested. The RL direction showcased a higher fracture energy than the TL direction, but it did at the same time display more unstable results. Two different shapes of fracture areas of the Nordtest specimens were tested, the rectangular shape as described in the standard, and a triangular shape. The unstable results were mainly from RL loading with a rectangular fracture area. The specimens with a higher density showcased both tendencies for a higher load capacity and a higher fracture energy.
The experimentally obtained fracture energy was then implemented to calculate the splitting capacity of dowel-type joints, which were made from the same boards used for manufacturing the Nordtest specimens. The dowel joints were then created, tested and examined. The calculated and experimental data were then compared. The calculated capacity was higher than the experimental capacity, maybe due to an unknown/assumed shear modulus. Beams with a higher density and a prescribed minimum dowel edge distance (from Eurocode 5) also showcased a higher load carrying capacity. Beams with a shorter dowel-to-edge did not showcase a higher load capacity in relation to a higher density. The beams with a longer edge distance had a higher capacity, due to premature splitting being avoided, which was indicated by a larger dowel hole deformation. The beams with a smaller edge distance tended to have a smaller embedment deformation and a lower capacity.}},
author = {{Esbjörnsson, Emma and Svensson, Johan}},
issn = {{0281-6679}},
language = {{eng}},
note = {{Student Paper}},
series = {{TVSM-5000}},
title = {{EXPERIMENTAL TESTING OF BIRCH WOOD}},
year = {{2024}},
}