Dynamic modulus assessment by stress waves in Acer saccharum Marshall and Thuja plicata L. wood

Abstract

The research goal was to assess the stress wave speed in the longitudinaland radial directions of Acer saccharum Marshall and Thuja plicataL. wood, and weighting this parameter with the wood density, todetermine the dynamic modulus of elasticity. For each species, 32 addocwood specimens were prepared with an average moisture contentof 11 % in which stress waves tests were realized. The experimentaldesign consisted in normality and difference of means tests. The responsevariables were the wood density, and for the longitudinal andtangential directions, the speed of the stress waves and the dynamicmodulus. The wood species was considered the variation factor. Thestress waves method allowed the dynamic characterization of A. saccharumand T. plicata wood. Significant statistical difference was foundbetween the response variables. The density of A. saccharum wood isgreater than the corresponding to T. plicata wood. In the longitudinaldirection, the stress wave speed and dynamic modulus of A. saccharumwood are lower than the T. plicata ones. In the tangential direction, thestress wave speed of A. saccharum is bigger than the T. plicata wood.In contrast, the dynamic modulus is smaller. When compared to thetangential direction, the stress wave speed and dynamic modulus arebigger in the longitudinal direction for both species.