Estimation of moisture content in sugi wood with sound velocity during the natural drying process

Sound velocity and longitudinal natural frequency in the fiber direction of the sugi wood specimens were measured to obtain the Young's moduli, E-V and E-F, in the moisture content region above the fiber saturation point. We discuss the relationship between Young's moduli and moisture content. Moreover, we tried to estimate the moisture content from the sound velocities measured during the drying process. In the moisture content region above the fiber saturation point, the Young's moduli obtained from longitudinal natural frequencies were almost constant, but those obtained from sound velocities increased with moisture content. It is concluded that we can estimate the moisture content from sound velocities in the moisture content range above 50% during the natural drying process using the values in the initial condition, such as moisture content, longitudinal natural frequency, propagation time of the sound wave and E-V/E-F.