Synergistic Effect of Strand Angle and Panel Density on Bending Properties of Strand-Based Wood Composites

Abstract

The impacts of panel density and strand alignment, and their synergistic effect, on bending strength and stiffness of strand-based wood composites were investigated experimentally. Fifteen unidirectional strand panels with a range of densities were manufactured. Bending specimens were cut at an angle with respect to the alignment direction at 15-degree increments from 0 to 90 degrees. Bending strength and stiffness with extended ranges of density (480 to 672 kg/m3) and strand alignment (0 to 90 degrees) enabled these production factors to be simultaneously investigated. The response of the bending properties to changes in density greatly depended on strand angle. A smaller strand angle exhibited a greater rate of bending property change with density. This synergistic effect provided a supplementary basis for focusing efforts in improving strand alignment on the thin layers near the high-density surfaces to enhance bending properties. The data presented in this article should be especially useful when dealing with unidirectional wood strand/veneer products, such as oriented strand lumber, where strand alignment and density are crucial for the intended application.