GLOSSARY OF TERMS
Bending Strength A measure of the resistance of wood to an
applied bending stress which is a combination of three primary stresses,
i.e., compressive, tensile, and shear stresses.
Density As applied to timber,
density is the mass of wood substance and moisture enclosed within a
piece expressed in kilograms per cubic meter. As the mass will vary
dependant on the amount of moisture in the piece, density is often
expressed at a specified moisture content, usually 12%.
Hardness A property of wood that
enables it to resist indentation. It is measure in kN and is often
determined by the Janka hardness test.
Maximum Crushing Strength A
measure of the ability of a piece of wood to withstand loads in
compression parallel to the grain up to the point of failure.
Shear Stress Result from forces which tend to
cause one portion of a body to move with respect to another in a
direction parallel to their plane of contact.
Shrinkage The reduction in
dimension or volume which takes place in timber when the moisture
content is reduced below fibre saturation point, expressed as a
percentage of the original dimensions or volume. Linear shrinkage occurs
in three directions radial, tangential and longitudinal.
Work to Maximum Load In bending,
it represents the ability of wood (or other materials) to absorb shock
with some permanent deformation and more or less injury to the piece. It
is a measure of the combined strength and toughness of wood under
bending stresses.
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