Determination of elastic constants for scots pine wood using ultrasound

Abstract

Elastic constants of Scots pine (Pinus sylvestris L.) wood grown in Turkey were investigated using non-destructive ultrasound tests. Elastic modulus in longitudinal and perpendicular directions (EL, ER, ET), shear modulus in principal planes (GLR, GLT, GRT) and Poisson ratios (?LR, ?RL ?LT, ?LT, ?RT, ?TR) were calculated using cubic samples (20 mm) which were conditioned at 65 % relative humidity and 21 °C. Longitudinal and transverse ultrasonic sound velocities in fiber (L), radial (R) and tangential (T) directions were measured using 2.25 MHz and 1 MHz sensors, respectively. Transverse sound wave velocities at an angle of 45° to the L, R and T directions were also measured with a 1 MHz sensor in order to calculate the Poisson ratios. The predicted elastic modulus based on ultrasound in L, R, T directions were 10600, 1300 and 470 N/mm2, respectively. The predicted shear modulus based on ultrasound in LR, LT, RT planes were 1180, 1050 and 350 N/mm2, respectively. Poisson ratios varied between 0.04 to 0.95. Comparing the data available in the literature, elastic constants of scots pine determined using ultrasonic method were within the acceptable values.