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Finite element modeling (FEM) simulation of interactions between wood and microwaves
Luleå tekniska universitet. Luleå.
2006 (English)In: Journal of Wood Science, Vol. 52, 406-410 p.Article in journal (Refereed) Published
Abstract [en]

The aim of this study was to use finite element modeling (FEM) as a tool to analyze microwave scattering in wood and to verify the model by measurements with a microwave scanner. A medical computed tomography scanner was used to measure distribution of density and moisture content in a piece of Scots pine (Pinus sylvestris). Dielectric properties were calculated from measured values for cross sections from the piece and used in the model. Images describing the distribution of the electric field and phase shift were obtained from the FEM simulation. The model was verified by measurements with a scanner based on a microwave sensor. The results show that simulated values correspond well to measured values. Furthermore, discontinuities in the material caused scattering in both the measured and the simulated values. The greater the discontinuity in the material, the greater was the need for computational power in the simulation.

Place, publisher, year, edition, pages
2006. Vol. 52, 406-410 p.
URN: urn:nbn:se:umu:diva-46078OAI: diva2:436950
Available from: 2011-08-25 Created: 2011-08-25 Last updated: 2011-09-07
In thesis
1. Microwave sensors for scanning of sawn timber
Open this publication in new window or tab >>Microwave sensors for scanning of sawn timber
2007 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

A microwave imaging sensor that measures the signal transmitted through a board was investigated with respect to the ability to predict the distribution of moisture and density in sawn lumber. Furthermore, the response from the sensor was related to strength properties of the boards. Multivariate statistics was used to relate the measured variables to various properties. A finite element model based on X-ray computed tomography images was developed to describe the interactions between microwaves and wood. The model made it possible to simulate the response from the sensor under varying conditions.

The results show that microwaves can be used for prediction of density and moisture content. They can also be used for prediction of strength properties, mainly from the correlation to density, but also from the influence on microwaves of structural variations in the wood. The finite element model is useful in the evaluation of microwave sensors for wood, drying equipment or other applications where electromagnetic waves interact with wood.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2007. 40 p.
, Doctoral thesis / Luleå University of Technology, 2007:9
microwave scanning; wood; density; moisture content; strength grading; finite element
National Category
Control Engineering
urn:nbn:se:umu:diva-46102 (URN)1402-1544 (ISBN)
Public defence
2007-04-18, Hörsal A, Forskargatan 1, Skellefteå, 10:00 (English)
Available from: 2011-08-29 Created: 2011-08-26 Last updated: 2011-08-29Bibliographically approved

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