Determination of modulus of elasticity in woods by destructive and non-destructive methods

Abstract

The purpose of this study was to correlate modulus of elasticity of Eucalyptus grandis W. Hill ex Maiden and Pinus elliottii Engelm. woods obtained by destructive and non-destructive methods. For such ultrasonic equipment with planes faces transducers of 50 kHz were used. The ultrasonic speed
was determined considering the transmission of the wave along the length of the samples with nominal dimensions of 5 x 5 x 20 cm (thickness x width x length). To evaluate the sensitivity of the ultrasonic method, the specime were submitted to destructive conventional compression to grain tests, with determination of modulus of elasticity (destructive and non-destructive methods). The modulus of elasticity obtained by ultrasonic method, for Eucalyptus grandis and Pinus elliottii woods, were higher than the modulus of elasticity obtained from conventional tests. Although the difference of absolute values between the methods, due to wood viscoelastic nature, ultrasonic method was efficient and fast for evaluating differences in the wood quality.