Factors Influencing Bending Properties of White Spruce Lumber

Authors

  • Hui Zhou
  • Ian Smith

Keywords:

Bending properties, softwood lumber, drying defects, knot area

Abstract

Influences of drying treatments, slope of grain, knots, juvenile wood percentage and other factors on strength properties of lumber were studied.

Conventional drying schedules, knots, warp, and juvenile wood significantly influenced the bending strength and stiffness of the lumber. Both modulus of rupture (MOR) and modulus of elasticity (MOE) decreased with any increase in the projected knot area (PKA). The mean MOR of specimens with PKA > 50% was only half of the mean MOR of specimens with PKA < 20%. The corresponding ratio for MOE was about 0.6. Both MOR and MOE decreased with an increase in warp or juvenile wood percentage. A clear dependence of strength on general slope of grain was not evident under the test conditions in this project.

References

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Published

2007-06-28

Issue

Number 4 / October 1991

Section

Research Contributions

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