Hygro-mechanically coupled modelling of creep in wooden structures, Part II: Influence of moisture content

In the first part of this publication, a modelling approach for the simulation of linear viscoelastic, non-linear viscoelastic–viscoplastic behaviour of wooden structures under consideration of creep failure is derived. In the framework of the paper at hand, which represents the second part, this formulation is enhanced by means of the consideration of hygro-mechanical coupling. With respect to the multiphysical characteristics of wood, mechano-sorptive effects due to simultaneous mechanical loading and moisture changes are captured in addition to the influence of the magnitude of MC on mechanically induced creep. In contrast to the majority of approaches, the separability of mechanically induced and mechano-sorptive deformation components is not presumed, which matches with recent experimental observations. The entire approach is applied for the investigation of the stress-level-dependent time to failure of beams subjected to different constant climates and climate changes basing on experimental investigations. Finally, the formulation is used to study the structural behaviour of a hygro-mechanically loaded face staggered joint.