Effect of temperature on mechanical damping of wood : measurement by pulse transmission method at 1 MHz

HANDLE Web Site Open Access

Bibliographic Information

Other Title
  • 木材の力学的減衰におよぼす温度の影響 : 1MHzでのパルス透過法による測定
  • 木材の力学的減衰におよぼす温度の影響--1MHzでのパルス透過去による測定
  • モクザイ ノ リキガクテキ ゲンスイ ニ オヨボス オンド ノ エイキョウ 1

Search this article

Description

The dynamic mechanical behavior of Buna-wood (Fagus crenata Blume) has been investigated as a function of temperature at a frequency of ultrasonic region. The ultrasonic attenuation in wood specimen was measured by means of pulse transmission method for a 1MHz-longitudinal wave. The testing temperatures ranged from near -50°C to as high as 100°C, and the moisture contents of wood specimens were from almost 0% (oven-dry) to 21%. Main results obtained are as fcllows： (1) The maximum mechanical damping of wood was observed at low temperatures(-10 - -20°C). The occurrence of the maximum damping may be largely associated with the action of moisture which is adsorbed on wood substances. (2)The position of the maximum mechanical damping in wood shifted with moisture content. At moisture contents below about 6%, the position of the maximum damping was situated near -10°C, and at moisture contents greater than about 6%, this position shifted to lower temperatures with increasing moisture content. This behavior is believed to be associated with the mechanism of the adsorption of moisture in wood. (3) For a high frequency of 1 MHz, the shift to lower temperatures of the position of the maximum mechanical damping caused by the adsorption of moisture on wood became smaller, as compared to the results obtained at the low frequency range of 3.5 Hz to 110 Hz.

Journal

Keywords

Details 詳細情報について

Report a problem

Back to top