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The variation in lumber quality within the supply of eucalypt is large. Effective segregation of the lumber according to “fitness for purpose ” is fundamental to enabling the capture of greater value for the finger-jointed. This paper deals with the longitudinal vibration technique as a means of assessing modulus of elasticity (MOE) of solid and finger-jointed specimens made with Eucalyptus grandis × E. urophylla and E. grandis. Dynamic MOE was calculated from resonance frequencies obtained from longitudinal vibration. The dynamic MOE was well correlated to the static bending MOE for solid and finger-jointed lumber from the two eucalyptuses. Correlation coefficients were obtained for the regression of dynamic MOE on static bending MOE for solid and finger-jointed lumber, and were statistically significant. Although the correlation coefficient of finger-jointed was lower than that of solid lumber, the results indicated that the static bending MOE of finger-jointed was strongly correlated with the dynamic MOE of solid lumber, namely, the solid lumber with higher dynamic MOE can produce higher bending MOE finger-jointed. It can be concluded that the longitudinal vibration technique may be useful as a nondestructive method for segregating lumbers for finger-jointed.
The variation in lumber quality within the supply of eucalypt is large. Effective segregation of the lumber according to “fitness for purpose” is fundamental to enabling the capture of greater value for the finger-joined. This paper deals with the longitudinal vibration technique As a means of assessing modulus of elasticity (MOE) of solid and finger-joinedted specimens made with Eucalyptus grandis × E. urophylla and E. grandis. Dynamic MOE was calculated from resonance frequency obtained from longitudinal vibration. The dynamic MOE was well correlated to the static bending MOE for solid and finger-joined lumber from the two eucalyptuses. Correlation coefficients were obtained for the regression of dynamic MOE on static bending MOE for solid and finger-joined lumber, and were significant. jointed was lower than that of solid lumber, the results indicated that the static bending MOE of finger-jointed was strongly correl ated with the dynamic MOE of solid lumber, namely, the solid lumber with higher dynamic MOE produce higher bending MOE finger-jointed. It can be concluded that the longitudinal vibration technique may be useful as a nondestructive method for segregating lumbers for finger-jointed .