Multiscale homogenization of wood transport properties: diffusion coefficients for steady-state moisture transport

This paper describes a multiscale homogenization model for macroscopic diffusion properties of wood. After a short introduction the physical background of steady-state diffusion processes in wood will be highlighted, resulting in a physically motivated macroscopic description of diffusion processes with only one diffusion equation and thus one diffusion tensor. This macroscopic diffusion tensor is derived by revisiting the morphological structure of wood in the framework of continuum micromechanics. The starting point is the cellular structure of wood; further homogenization steps include wood rays and the succession of annual rings. The quality of the model is assessed by a comparison of model predictions and measured values at different temperatures and moisture contents