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The effects of joints on the moisture behaviour of rain exposed wood: a numerical study with experimental validation

Niklewski, Jonas LU and Fredriksson, Maria LU (2019) In Wood Material Science & Engineering
Abstract
Joints in timber structures are particularly vulnerable to degradation due to their tendency to trap moisture. The mechanisms involved, and their effect on the moisture conditions of wood, are here investigated numerically. The horizontal member of a rail and post-type configuration is modelled numerically by a two-dimensional diffusion model with material properties for Norway spruce. Contact areas are assumed to be fully wetted when the specimen is exposed to free water but are unable to interact with the ambient air. Water that is absorbed through such areas cannot dry out through the same surface and is instead redistributed. The model was validated against experimental data, both previously unpublished data and data obtained from the... (More)
Joints in timber structures are particularly vulnerable to degradation due to their tendency to trap moisture. The mechanisms involved, and their effect on the moisture conditions of wood, are here investigated numerically. The horizontal member of a rail and post-type configuration is modelled numerically by a two-dimensional diffusion model with material properties for Norway spruce. Contact areas are assumed to be fully wetted when the specimen is exposed to free water but are unable to interact with the ambient air. Water that is absorbed through such areas cannot dry out through the same surface and is instead redistributed. The model was validated against experimental data, both previously unpublished data and data obtained from the literature, including both laboratory and outdoor exposure. The numerical solutions were, in general, consistent with the measured data. The model provides a simple, yet accurate, method to estimate the moisture conditions in certain types of wood joints. In addition, the spatial distribution of time spent above 25% moisture content was calculated, in order to investigate the suitability of the model for durability applications. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
epub
subject
keywords
wood, moisture transport, numerical, joint, Numerical approximation, joint, wood, moisture transport
in
Wood Material Science & Engineering
publisher
Taylor & Francis
external identifiers
  • scopus:85063742523
ISSN
1748-0272
DOI
10.1080/17480272.2019.1600163
language
English
LU publication?
yes
id
da960b96-b510-4032-969c-40ca699ce285
date added to LUP
2018-11-13 16:44:25
date last changed
2019-05-14 04:47:24
@article{da960b96-b510-4032-969c-40ca699ce285,
  abstract     = {Joints in timber structures are particularly vulnerable to degradation due to their tendency to trap moisture. The mechanisms involved, and their effect on the moisture conditions of wood, are here investigated numerically. The horizontal member of a rail and post-type configuration is modelled numerically by a two-dimensional diffusion model with material properties for Norway spruce. Contact areas are assumed to be fully wetted when the specimen is exposed to free water but are unable to interact with the ambient air. Water that is absorbed through such areas cannot dry out through the same surface and is instead redistributed. The model was validated against experimental data, both previously unpublished data and data obtained from the literature, including both laboratory and outdoor exposure. The numerical solutions were, in general, consistent with the measured data. The model provides a simple, yet accurate, method to estimate the moisture conditions in certain types of wood joints. In addition, the spatial distribution of time spent above 25% moisture content was calculated, in order to investigate the suitability of the model for durability applications.},
  author       = {Niklewski, Jonas and Fredriksson, Maria},
  issn         = {1748-0272},
  keyword      = {wood,moisture transport,numerical,joint,Numerical approximation,joint,wood,moisture transport},
  language     = {eng},
  month        = {04},
  publisher    = {Taylor & Francis},
  series       = {Wood Material Science & Engineering},
  title        = {The effects of joints on the moisture behaviour of rain exposed wood: a numerical study with experimental validation},
  url          = {http://dx.doi.org/10.1080/17480272.2019.1600163},
  year         = {2019},
}