Hygro- and Thermo-Mechanical Modeling of Wood at Large Deformations: Application to Densification and Forming of Wooden Structures

The contribution at hand provides a basis for modeling hygro- and thermo-mechanical processes, especially at large deformations. Therefore, hygro- and thermo-mechanical fundamentals of wood are introduced under consideration of moisture, temperature and displacement dependent processes. The influence of moisture on the density of wood is taken into account as well as a characterization of the interaction of temperature and moisture. Finite element formulations are derived,s together with constitutive laws, as a basis for the numerical solutions. A verification as well as a validation of the specific formulations for the hygro- and thermo-mechanical behavior of different wood species is presented. Finally, the applicability of the proposed finite element descriptions is demonstrated at the densification and forming process of wood.