بررسي خواص راستايي تخته خرده چوب به وسيله روش استاتيك و اكوستيك

Anisotropy Characterization of Particleboard by Static and Acoustic Methods

Anisotropy of three types of Iranian particleboards was estimated as the ratio of Youngʹs moduli, velocities of bulk waves (shear and longitudinal waves) and of acoustic invariant. The ultrasonic through-transmission method was used to measure the ultrasonic velocities in principle symmetry axis. Young s moduli were determined with the 4-point static bending test. The results show that the velocity parallel to the production direction is higher than that in perpendicular direction and is lowest through thickness because particles are directed in production direction. The structure of particleboard influences ultrasonic velocities, so the anisotropy behavior of particleboard can be explained by the ratios of ultrasonic velocities. The used different methods for description of anisotropy by ultrasonic parameters and static modulus of elasticity show to be in good agreement.