Effect of specimen configuration on the measurement of off-axis logarithmic decrement of solid wood measured by longitudinal and flexural vibration tests

摘要

Douglas fir (Pseudotsuga menziesii) lumber was tested in terms of off-axis modulus of elasticity (MOE_(off-axis)) and off-axis logarithmic decrement (λ_(off-axis)) by longitudinal and flexural vibration (VT_(long) and VT_(flex)) methods. Similar to the results obtained in a previous study, these results indicate that the values of MOE_(off-axis) are dependent on the length-to-width ratio of specimens when the value of off-axis angle (θ) is approximately 15°. Although the λ_(off-axis) values are also dependent on the length-to-width ratio, the dependence is not pronounced over a specific range of θ. To measure the λ_(off-axis) value accurately, as well as the MOE_(off-axis) value, the specimen should be sufficiently slender.