Predicting bending stiffness of randomly oriented hybrid panels

This study was conducted to develop a simple model to predict the bending modulus of elasticity (MOE) of randomly oriented hybrid panels. The modeling process involved three modules: the behavior of a single layer was computed by applying micromechanics equations, layer properties were adjusted for densification effects, and the entire panel was modeled as a three-layer symmetric composite using laminate theory. The model accounts for panel vertical density distribution and the inclusion of two fiber reinforcements. Model inputs were experimentally determined from physical and mechanical tests on hot-pressed resinated strands and bark. Experimental verification was conducted using laboratory panels of wood strands and bark from fire-impacted trees at an 80:20 wood:bark weight ratio. Comparisons with experimental data showed that MOE of hybrid panels was adequately predicted with deviations of 13-23% compared with observed MOE. Results validated application of micromechanic equations and laminate theory to predict the MOE of randomly oriented hybrid oriented strandboard of wood strands and bark. This study also contributes to the knowledge of predicting and tuning stiffness properties of hybrid panel-based composites, thereby promoting utilization and sustainable use of plant-based raw materials.