| In this study, the feasibility of applying Classical Lamination Theory to predict the bending modulus of Oriented Strandboard was evaluated. First, the elastic mechanical properties (modulii and Poisson's ratio) and the longitudinal modulus (EL) versus density relationship of Oriented Strandboard's main constituent, Aspen flakes were measured. Image analysis was then applied to determine the grain orientations of the flakes on the surface of Oriented Strandboard and the bending modulus was measured. After these measurements, a pair of one-millimeter thick layers was planed from the top and the bottom surfaces of Oriented Strandboard. The image analysis and bending modulus measurements were repeated until the specimens were two-millimeter thick. The density of each layer was also measured during the experiment. With the knowledge of the properties of Aspen, the density of the layers, and their orientation distributions. Classical Lamination Theory was applied to determine the tensile modulus of each layer. After determining the tensile modulus of each layer, the bending modulus of the Oriented Strandboard specimens was predicted by the parallel axis theorem.; The predicted bending modulus was compared to the measured bending modulus. The deviation for the five specimens cut parallel to the principle alignment direction of the surface flakes was nine percent, and the deviation for the five specimens cut perpendicular to the principle alignment direction of the surface flakes was eight percent. The excellent agreement between the predicted and the measured bending modulus proved that both image analysis and Classical Lamination Theory are useful tools to evaluate the bending modulus of Oriented Strandboard. |
