Comparison of temperature dependent Young’s modulus of oriental beech (Fagus orientalis L.) that determined by ultrasonic wave propagation and compression test

Abstract

Mechanic properties of wood material change depending on lots of natural and environmental factors. Temperature is one of these factors and in this study, effect of temperature on Young’s modulus of Oriental beech wood was investigated. Longitudinal direction (L) compression test samples exposed to 120, 150, 180 and 210°C temperature for 2, 5 and 8 hours. A drying oven that operates in an atmospheric environment was used for temperature treatment. Static and dynamic Young’s modulus values were determined or predicted by compression test and ultrasonic wave propagation method, respectively. Results compared with each other by regression analysis to determine how successful the ultrasonic measurement is. All test samples, 20x20x60 mm, acclimatized at 20 ±2°C and 65% RH conditions. Deformation values of the tested samples were obtained by using bi-axial extensometer and then stress-strain curves were created. Static Young’s modulus was calculated by using stress-strain values from the linear elastic region of these curves. Edyn was predicted by using ultrasonic wave velocity and sample density values. Velocities were calculated by using time of flight values obtained by ultrasonic measurements. Reasonable and good relations between dynamic and static modulus of elasticity were determined by the coefficient of determination results that ranged from 0.78 to 0.94 in terms of temperature and exposure duration. Consequently, L direction Young’s modulus of Oriental beech wood that exposed to temperature can be well predicted by using ultrasonic measurement.

Keywords

• oriental beech
• young’s modulus
• non-destructive test
• ultrasonic
• doğu kayını
• young’s modülü
• tahribatsız muayene
• ultrasonik