General model of wood in typical coupled tasks, Part II. - Weak solution

The main aim of this work is focused on weak solution of coupled physical task the microwave drying of wood with stress-strain effects and moisture/temperature dependency. Due to well known weak solution for separated physical fields without coupled effect, author concerns with coupled stress-strain relation coupled with moisture and temperature distribution. For scale dependency the subgrid upscaling method was used. Solved region is assumed to be divided into discontinual subregions according to investigated scale. This approach sugests sequential type of solution for highly coupled task. This way, very huge structures (huge according to geometry and also physics) can be solved in reasonable time and with memory consumptions. Main emphasis was putted on evaluation of structural response of the whole complex. Due to influence of moisture, temperature and time the coupled physical task of structural response is solved. Sugested aproach is of course usable not only for structural response, but for other physical fields, which were taken into account. Weak solution is based on slightly modified Ritz-Galerkin method. The work is continuing of the previous article General model of wood in typical coupled tasks: Part I. - Phenomenological approach.

Keywords: FEM, multiphysics, microwave wood drying, upscaling, homogenisation

Grants and funding:

The work is supported by project GAČR GP106/06/P363 (P526563605) - Homogenization of material properties of wood for tasks from mechanics and thermodynamics