Influence of Moisture Content and Selected Wood Defects for the Accuracy of the Eigen-Frequency Method - Analysed on Samples Of Norway Spruce (Picea Abies)
Ute Seeling
ABSTRACT Dynamic methods to determine the modulus of elasticity are rapid and accurate. In the future those could become interesting to be included in the industrial production process in sawmills as on-line quality control of timber. Before the possibilities have to be analysed to predict the strength by using the dynamic modulus of elasticity. The accuracy of the Eigen-Frequency method has been tested for samples of Norway Spruce with defects (pith, juvenile wood, knots and compression wood) on the one hand and at different moisture contents at the other hand.
Defects reduce the elasticity severely. The elasticity varies in a wide range. Defects had no clear influence on the variation of the elasticity. The occurrence of compression wood reduces the correlation between strength and elasticity. Decreasing moisture content (18% - 10%) reduces elasticity about 3 % to 5 %. This tendency was equal for all samples and didn't depend on the type defect.
Publication Source: WCTE '98 - 5th World Conference on Timber Engineering, 1998 August 17-20, Montreaux, Switzerland.
Vol. 2, Pages 326.....
Publisher: Presses polytechniques et universitaires romandes - [Homepage]
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