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Wood Structure

Wood Structure. Softwood. Hardwood. Variability in wood products. Solid wood. frequency. strength. Variability in wood products. mean. lower 5 th percentile. Solid wood. ÷ safety factors. frequency. allowable design stress. strength. Variability in wood products. mean. mean.

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Wood Structure

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  1. Wood Structure Softwood Hardwood

  2. Variability in wood products Solid wood frequency strength

  3. Variability in wood products mean lower 5th percentile Solid wood ÷ safety factors frequency allowable design stress strength

  4. Variability in wood products mean mean lower 5th percentile ÷ safety factors Solid wood lower 5th percentile Wood composite A ÷ safety factors frequency strength allowable design stress allowable design stress

  5. Anisotropy (St. Regis Paper Co.) (Indospectrum.com) (Côté)

  6. Anisotropy Parallel to grain Perpendicular to grain

  7. Wood sections/surfaces/planes Transverse section T T R R R R T T L L L T = tangentialR = radialL = longitudinal Longitudinal section

  8. Anisotropy – perpendicular to grain Radial Tangential

  9. Hygroscopicity Hydrogen Bond  H  O  H H  O  H Water 

  10. Hygroscopicity Hydrogen Bond  H Wood O   H  O H 

  11. Water in cell wall H O H H H H O O O O H O H H H O H H H O O O H O H O H H O H H H H H O O O O O H H H

  12. Water in wood Free water Bound water Cell wall Cell lumen Oven dry > Fibre saturation point0% m.c. 0 – 30% m.c. > 30% m.c.

  13. Effect of moisture content on wood properties Fibre Saturation Point

  14. Comparative Environmental Impact AssessmentLife Cycle Analysis Canadian Wood Council

  15. Comparative Environmental Impact Assessment Canadian Wood Council

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