Acoustic wave method for non-destructive evaluation of flattened bamboo veneers

Abstract

This study examined the feasibility of acoustic stress wave velocity (V) evaluation commonly used to grade wood veneer for predicting the flexural Modulus of Elasticity (MOE) of flattened Moso bamboo. The correlation between MOE and V was low in bamboo compared with Douglas fir wood veneers, due to much lower grain angle deviation in bamboo. Bamboo had 30% lower MOE than Douglas-fir, likely linked to a combined effect of shorter cells and higher average microfibril angle of parenchyma cells in bamboo. Segmenting by density can effectively group flattened bamboo veneers into different MOE grades (R2 = 0.52) but assaying for both density and V gives more reliable prediction of apparent MOE (R2 = 0.86).