Wood Composite Plates with Reversible Humidity-driven Deformation

Abstract

Four types of beech/spruce composite plates were fabricated from beech with different wood textures under different initial ambient relative humidity, and the impacts of the changes in ambient relative humidity on the deformation characteristics and mechanical properties of the composite plates were studied. It was found that the reversible bending deformation of the composite plates can be achieved by adjusting the ambient humidity. The bending deformation characteristics of the composite plates were related to the initial fabrication conditions and humidity expansion characteristics of the wood, and conformed to the improved Timoshenko theoretical model for bilayer humidity expansion materials. The experiments on humidity-driven deformation of the counter-balanced composite plates showed that external load would hinder the deformation of the composite plates driven by the ambient humidity, but the composite plates still had a good load-bearing capacity.