Vibrational Properties of Japanese Cedar Juvenile Wood at High Temperature.

The vibrational properties of Japanese cedar wood at high temperature were measured. The specimen, its support system, a magnetic driver, and a deflection sensor were placed in an electric drying oven, where vibration tests were conducted. The heating temperatures ranged from 25 ºC to 200 ºC in 25 ºC increments. The resonance frequency decreased with higher heating temperature and decreased most dramatically in the temperature range of 150 ºC to 200 ºC. The loss tangent had a minimum value at 100 ºC and changed more in the temperature range from 150 ºC to 200 ºC than in the range from 25 ºC to 150 ºC. The changes in the resonance frequency and loss tangent of the specimens with larger distance from the pith (d) were smaller than those around the pith. These tendencies are believed to have occurred because the portion with a larger d had a smaller number of intercellular layers than the portion around the pith. [ABSTRACT FROM AUTHOR]