A Comparison of Three Methods for Determining Elastic Constants of Wood

Abstract

The results of an experimental/theoretical investigation of wood properties are presented. The methodologies applied in the course of this study consist of static (flexure test), vibration (resonance test), and ultrasonic wave propagation techniques. On the theoretical side, a parametric study utilizing Timoshenko-type bean analysis, resonance vibration, and sonic time-of-flight in bounded media is carried out. Various experiments performed on specimens of Douglas Fir have yielded data which are correlated with the theoretical models. Based on these correlations, values for the elastic moduli on the three wood axes are determined. A comparison of the three measurement methods and their respective results is presented. A partial explanation for the disparity of results between the three test methods is that they do not each measure precisely the same property of a wood specimen.