بررسي سرعت امواج اولتراسونيك و خواص مكانيكي در زواياي مختلف تخته خرده چوب

An Investigation of Ultrasonic Velocity and Mechanical Properties along Different Angles in Particleboard

Ultrasonic wave velocity as well as some mechanical properties such as modulus of elasticity, modulus of rupture and shear strength in particleboard were determined at different angels along manufacturing direction and at angle intervals of 15 0. The results demonstrated that ultrasonic wave velocity as well as modulus of elasticity are highest along manufacturing direction, decreasing with increase in angle, and while the lowest figures occur in a direction perpendicular to the manufacturing direction. This trend was not observed for either modulus of rupture or shear strength. A higher correlation was observed between modulus of elasticity and ultrasonic velocity as compared with the correlation between ultrasonic velocity and either shear strength or modulus of rupture. The correlation between ultrasonic velocity and modulus of elasticity in surface layer of particleboard was higher than that in core layer. The ratio of moduli of elasticity along different angles showed a higher anisotropy than the ratios of either ultrasonic wave velocities or moduli of rupture.