Low Temperature Internal Friction and Dynamic Modulus for Beach Wood
Keywords:Fagus silvatica, dynamic elastic modulus, internal friction, temperature effects, moisture content, moisture effects
AbstractThe dynamic elastic modulus and the internal friction of beech wood beams conditioned to various equilibrium moisture contents have been measured in the temperature range from 25 C to -130 C. The response curves show a marked transition around -90 C for wood with moisture contents at or above the fibre saturation level. The transition is similar to those found for other microporous water-adsorbing materials such as hardened cement paste and porous glass. Decreasing moisture contents in the wood reduce the magnitude of the transition and shift the transition to higher temperatures. We believe the transition to be caused by a gradual solidification ("glass transition") of the adsorbed water.
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