Modelling of Dynamic and Quasistatic Events with Special Focus on Wood-Drying Distortions

This paper describes a new method, called theCT-direction method, in which the fiber directions in woodin three-dimensional space are calculated from the pixelinformation on a series of two-dimensional computed to-mography images. Local fiber directions are calculated fromthe principal directions of inertia of measurement spheresdistributed throughout the body of the wood object. Thecalculated fiber directions are probably due to densitystreaks in the material, such as fiber bundles, which aredirected in the fiber direction, and not the density of indi-vidual fibers, which are too small to be detected. The fiberdirections vary locally, and density streaks from knots,growth rings, and compression wood influence the results,which adds spread to the results. The fiber directions arepresented as spiral grain angles and conical angles and arecompared with spiral grain angles measured with the trac-heid-effect method. The comparisons show that the CT-direction method is a nondestructive way to measure fiberdirections locally and in the interior of the body of a piece ofwood.