Mechanical Properties in Relation to Selected Wood Characteristics of Black Spruce


  • Jérôme Alteyrac
  • Alain Cloutier
  • Chhun-Huor Ung
  • S. Y. Zhang


Microfibril angle, modulus of elasticity, modulus of rupture, ring density, ring width, cambial age, mixed model


The relation between ring width, ring density, microfibril angle, and bending properties was analyzed at 2.4-m height on twelve 80-year-old black spruce trees. The moduli of elasticity and rupture were measured in the southernmost radial direction on extracted specimens of size 10 x 10 x 150 mm3 from pith to bark. Ring density and ring width were measured by X-ray densitometry, and microfibril angle was measured by the Silviscan technology. The impact of these three traits on the moduli of elasticity and rupture was evaluated by explicitly separating the radial variation from the variation among trees using a mixed model analysis. The results obtained show first that the modulus of elasticity is negatively correlated to microfibril angle. This result supports the assumption that the relation between modulus of elasticity and microfibril angle is not dependent on radial growth rate. Secondly, ring density has a lower contribution in predicting the modulus of elasticity than the modulus of rupture. In both cases, ring width was not a significant factor of variation of the moduli of elasticity and rupture.


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