New aspects for the cracking behavior of wood

Saila Jämsä, Mia Löija, Tuomo Ojanen

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

Abstract

Wetting and drying of wood cause stresses and deformations in the material.These changes may cause cracks in the wood and wood coatings.Crack formation is a serious defect that may reduce the service life of the structure.Cracking of wood has usually been studied as a result of stresses induced by moisture content difference between surface and interior.Minor attention has been paid to the stresses between earlywood and latewood.VTT has developed an application based on NIR spectroscopy to determine the moisture content in wood.FT-NIR mapping made it possible to distinguish earlywood and latewood of wood samples and enabled detecting of the moisture distribution along the surface of materials.The NIR- method confirmed the assumption that under the same relative humidity conditions the latewood had a higher moisture content than early wood.In a series of moisture load tests, the cracking of wood was observed to start close to the border of earlywood and latewood, but typically in the early wood region.This is an indication of internal stresses caused by moisture gradients between earlywood and latewood.The dynamic moisture behavior of timber material layer consisting of earlywood and latewood plies having (assumed) different moisture properties were numerically simulated.The results showed how the local moisture gradients might have very high levels and variations by the border of earlywood and latewood during dynamic moisture load conditions.
Original languageEnglish
Title of host publicationApplied Material Research at VTT
Subtitle of host publicationSymposium on Applied Materials
Place of PublicationEspoo
PublisherVTT Technical Research Centre of Finland
Pages214-225
ISBN (Electronic)951-38-6312-3
ISBN (Print)951-38-6311-5
Publication statusPublished - 2006
MoE publication typeB3 Non-refereed article in conference proceedings
EventInternal Symposium on Applied Materials - Espoo, Finland
Duration: 8 Jun 20068 Jun 2006

Publication series

SeriesVTT Symposium
Number244
ISSN0357-9387

Conference

ConferenceInternal Symposium on Applied Materials
CountryFinland
CityEspoo
Period8/06/068/06/06

Fingerprint

Wood
Moisture
Timber
Crack initiation
Service life
Wetting
Residual stresses
Atmospheric humidity
Drying
Spectroscopy
Cracks
Coatings
Defects

Cite this

Jämsä, S., Löija, M., & Ojanen, T. (2006). New aspects for the cracking behavior of wood. In Applied Material Research at VTT: Symposium on Applied Materials (pp. 214-225). Espoo: VTT Technical Research Centre of Finland. VTT Symposium, No. 244
Jämsä, Saila ; Löija, Mia ; Ojanen, Tuomo. / New aspects for the cracking behavior of wood. Applied Material Research at VTT: Symposium on Applied Materials. Espoo : VTT Technical Research Centre of Finland, 2006. pp. 214-225 (VTT Symposium; No. 244).
@inproceedings{d6801856628d48148d749a556030d3b9,
title = "New aspects for the cracking behavior of wood",
abstract = "Wetting and drying of wood cause stresses and deformations in the material.These changes may cause cracks in the wood and wood coatings.Crack formation is a serious defect that may reduce the service life of the structure.Cracking of wood has usually been studied as a result of stresses induced by moisture content difference between surface and interior.Minor attention has been paid to the stresses between earlywood and latewood.VTT has developed an application based on NIR spectroscopy to determine the moisture content in wood.FT-NIR mapping made it possible to distinguish earlywood and latewood of wood samples and enabled detecting of the moisture distribution along the surface of materials.The NIR- method confirmed the assumption that under the same relative humidity conditions the latewood had a higher moisture content than early wood.In a series of moisture load tests, the cracking of wood was observed to start close to the border of earlywood and latewood, but typically in the early wood region.This is an indication of internal stresses caused by moisture gradients between earlywood and latewood.The dynamic moisture behavior of timber material layer consisting of earlywood and latewood plies having (assumed) different moisture properties were numerically simulated.The results showed how the local moisture gradients might have very high levels and variations by the border of earlywood and latewood during dynamic moisture load conditions.",
author = "Saila J{\"a}ms{\"a} and Mia L{\"o}ija and Tuomo Ojanen",
year = "2006",
language = "English",
isbn = "951-38-6311-5",
series = "VTT Symposium",
publisher = "VTT Technical Research Centre of Finland",
number = "244",
pages = "214--225",
booktitle = "Applied Material Research at VTT",
address = "Finland",

}

Jämsä, S, Löija, M & Ojanen, T 2006, New aspects for the cracking behavior of wood. in Applied Material Research at VTT: Symposium on Applied Materials. VTT Technical Research Centre of Finland, Espoo, VTT Symposium, no. 244, pp. 214-225, Internal Symposium on Applied Materials, Espoo, Finland, 8/06/06.

New aspects for the cracking behavior of wood. / Jämsä, Saila; Löija, Mia; Ojanen, Tuomo.

Applied Material Research at VTT: Symposium on Applied Materials. Espoo : VTT Technical Research Centre of Finland, 2006. p. 214-225 (VTT Symposium; No. 244).

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

TY - GEN

T1 - New aspects for the cracking behavior of wood

AU - Jämsä, Saila

AU - Löija, Mia

AU - Ojanen, Tuomo

PY - 2006

Y1 - 2006

N2 - Wetting and drying of wood cause stresses and deformations in the material.These changes may cause cracks in the wood and wood coatings.Crack formation is a serious defect that may reduce the service life of the structure.Cracking of wood has usually been studied as a result of stresses induced by moisture content difference between surface and interior.Minor attention has been paid to the stresses between earlywood and latewood.VTT has developed an application based on NIR spectroscopy to determine the moisture content in wood.FT-NIR mapping made it possible to distinguish earlywood and latewood of wood samples and enabled detecting of the moisture distribution along the surface of materials.The NIR- method confirmed the assumption that under the same relative humidity conditions the latewood had a higher moisture content than early wood.In a series of moisture load tests, the cracking of wood was observed to start close to the border of earlywood and latewood, but typically in the early wood region.This is an indication of internal stresses caused by moisture gradients between earlywood and latewood.The dynamic moisture behavior of timber material layer consisting of earlywood and latewood plies having (assumed) different moisture properties were numerically simulated.The results showed how the local moisture gradients might have very high levels and variations by the border of earlywood and latewood during dynamic moisture load conditions.

AB - Wetting and drying of wood cause stresses and deformations in the material.These changes may cause cracks in the wood and wood coatings.Crack formation is a serious defect that may reduce the service life of the structure.Cracking of wood has usually been studied as a result of stresses induced by moisture content difference between surface and interior.Minor attention has been paid to the stresses between earlywood and latewood.VTT has developed an application based on NIR spectroscopy to determine the moisture content in wood.FT-NIR mapping made it possible to distinguish earlywood and latewood of wood samples and enabled detecting of the moisture distribution along the surface of materials.The NIR- method confirmed the assumption that under the same relative humidity conditions the latewood had a higher moisture content than early wood.In a series of moisture load tests, the cracking of wood was observed to start close to the border of earlywood and latewood, but typically in the early wood region.This is an indication of internal stresses caused by moisture gradients between earlywood and latewood.The dynamic moisture behavior of timber material layer consisting of earlywood and latewood plies having (assumed) different moisture properties were numerically simulated.The results showed how the local moisture gradients might have very high levels and variations by the border of earlywood and latewood during dynamic moisture load conditions.

M3 - Conference article in proceedings

SN - 951-38-6311-5

T3 - VTT Symposium

SP - 214

EP - 225

BT - Applied Material Research at VTT

PB - VTT Technical Research Centre of Finland

CY - Espoo

ER -

Jämsä S, Löija M, Ojanen T. New aspects for the cracking behavior of wood. In Applied Material Research at VTT: Symposium on Applied Materials. Espoo: VTT Technical Research Centre of Finland. 2006. p. 214-225. (VTT Symposium; No. 244).