Modelling The Shrinkage Mechanism In Wood Using The Theory Of Linear Elastic Materials With Voids

Abstract

Wood is a complex, porous material composed of cell walls and voids. The cell walls can be conceptualized as an elastic matrix containing voids or sites where bound water molecules are held. The void volume fraction in the theory of linear elastic materials with voids is utilized in the present paper to represent the space occupied by bound water. The mechanical response to the changes in this fraction due to drying is studied in the work. A realistic representation of wood drying is incorporated in the work by including time-dependent moisture diffusion and material heterogeneity. The coupled formulation captures the hygro-mechanical interaction through the void volume fraction as a fundamental kinematic variable. The numerical simulations presented illustrate the model’s ability to capture the complex behaviour of wood drying including shrinkage and warping with results that align with the recent experimental observations available in the literature.