Viscoelastic properties of bamboo

Dynamic viscoelastic properties of bamboo were determined in torsion and bending. Damping, measured by tan delta, in dry bam boo was relatively small, about 0.01 in bending and 0.02 to 0.03 in torsion, with little dependence on frequency in the audio range. in wet bamboo, damping was somewhat greater: 0.012-0.015 in bending and 0.03-0.04 in torsion. The anisotropy in damping implies a purely cellular model is insufficient; there is targe-scale molecular orientation or at least two distinct solid phases.