Prediction of MOE of eucalypt wood from microfibril angle and density

Abstract

Small clear specimens of 30×30×450 mm were prepared from plantation-grown Eucalyptus globulus, E. nitens and E. regnans that were between 15 and 31 years of age. Their modulus of elasticity (MOE) and modulus of rupture (MOR) were determined using static central-point-loading bending tests. Their microfibril angle (MFA) and density were determined using SilviScan on strip samples removed from the intact portion of the specimens after the bending tests. It was found that MFA alone accounted for 87 percent of the variation in MOE, while density alone accounted for 81 percent. Together, MFA and density (as Density/MFA) accounted for 92 percent of the variation in MOE. The MFA “impact diminishing” point1 appears to be 16 degrees for the wood material of three eucalypt species in this study. Density alone accounted for 80 percent of the variation in MOR, whereas MFA had little independent influence on MOR.