Influence of the compression ratio on the elastic properties of compressed wood
2006
Tunematsu, S.(Shimane Univ., Matsue (Japan). Faculty of Science and Engineering) | Yoshihara, H.
In this study, compressed wood with several compression ratios was fabricated, and the influence of compression ratio on the elastic properties of compressed wood was examined by symmetric and asymmetric four-point bending tests. Sitka spruce (Picea sitchensis Carr.) was used as the testing material. Compressed wood with several compression ratios was fabricated by applying a lateral pressure on the longitudinal-tangential plane in a hygro-thermal atmosphere. Rectangular beams were cut from the compressed wood, and Young's modulus in the longitudinal direction and Poisson's ratio in the longitudinaltangential (LT) and longitudinal-radial (LR) planes were measured by symmetric four-point bending tests of the beam, whereas the shear moduli in the LR and LT planes were measured by asymmetric four-point bending tests under various span lengths. The influence of compression ratio was marked and characteristic for Poisson's ratios and shear moduli as well as Young's modulus, which had been often measured in several previous studies. This indicates that the measurement of Poisson's ratios and shear moduli is important as well as that of Young's modulus for evaluating the quality of compressed wood.
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