- Original Article
- Published:
Choosing green sawing dimensions for Norway spruce from stochastic simulations
Journal of Wood Science volume 57, pages 94–99 (2011)
Abstract
The high accuracy of log positioning and the stability of saw blades in breakdown machinery in modern sawmills have reduced the need to add margins for sawing variations. Oversize green sawing dimensions are still needed, but mainly to allow for drying shrinkage. This has put a new focus on better adapting green sawing dimensions to the shrinkage behavior of wood. In this study, a method for optimization of green sawing dimensions using stochastic simulation is presented. Normal distributions were generated for planed dry dimensions, kerf width, and target moisture content. The minimum share of boards exceeding the specified dry dimensions was decided, and deformations in boards from all positions in the cross section in a number of logs were simulated. The simulated shrinkage allowance from stochastic simulations was compared to experimental results from an industry test and to finite element results based on material data for Norway spruce. The results showed that the green width of the sawn boards should increase when the number of boards in the center yield increases. The green thickness of boards should be thinner for center boards and outer boards than for inner boards.
References
Dinwoodie JM (2000) Timber: its nature and behaviour, 2nd edn. E&FN Spon, London
Vuorilehto J (2001) Size control of sawn timber by optical means in breakdown saw machines. Doctoral Thesis, Helsinki University of Technology, Department of Forest products technology
Hajek B, Esping B (1996) Choosing Green sawing dimensions for various moisture contents after drying. (in Swedish). Institutet för träteknisk forskning, Trätek
Grönlund A, Flodin J, Wamming T (2009) Adaptive control of green target sizes. In: Proceedings of the 19th Wood Machining Seminar, Nanjing Forestry University, Nanjing
Ekevad M, Lundgren N, Flodin J (2010) Choosing green sawing dimensions for best value yield of Norway spruce: Industrial measurements and physical modelling. In: Proceedings of the 11th International IUFRO Wood Drying Conference. Luleå University of Technology, Skellefteå, pp 168–173
Asmussen S, Glynn PW (2007) Stochastic simulation: algorithms and analysis. Springer, London
Danvind J, Ekevad M (2006) Local water vapour diffusion coefficient when drying Norway spruce sapwood. J Wood Sci 52:195–201
Anonymous (2007) ABAQUS analysis users’ manual, version 6.7. Available at http://www.simulia.com/. Accessed June 30 2010
Ormarsson S (1999) Numerical analysis of moisture-related distortions in sawn timber. Doctoral Thesis, Chalmers University of Technology, Department of Structural Mechanics, Göteborg
Ekevad M (2006) Modelling of dynamic and quasistatic events with special focus on wood-drying distortions. Doctoral Thesis, Luleå University of Technology, Division of Wood Science and Technology
Anonymous (1999) Wood handbook: Wood as an engineering material. Forest Products Laboratory, US Department of Agriculture, Madison
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Lundgren, N., Ekevad, M. & Flodin, J. Choosing green sawing dimensions for Norway spruce from stochastic simulations. J Wood Sci 57, 94–99 (2011). https://doi.org/10.1007/s10086-010-1142-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10086-010-1142-1