Hygro-elasticity and moisture diffusivity analysis of periodically heterogeneous materials by hierarchical microscale models

The present paper focuses on developing a method to solve micromechanical analyses for the computation of moisture diffusivity and hygro-elastic characteristics of periodically heterogeneous materials and the recovery of the moisture flux and the stress over the Repeating Unit Cell (RUC). The model is based on the Mechanics of Structure Genome (MSG) to build a procedure capable of de-coupling the multiscale analysis into different steps on global and local levels, resulting in less demanding problems. On the other hand, the methodology uses the Carrera Unified Formulation (CUF) to engage a refined beam theory with high-fidelity capabilities. Hence, the longitudinal direction of the reinforcement is described with one-dimensional (1D) finite elements. Besides, for the cross-section, a hierarchical discretisation coupled with a non-isoparametric mapping technique allows reaching a high level of accuracy in the geometric description of the curvature of the fibre or inclusion. Finally, both hygro-elastic and moisture diffusivity problems are validated through numerical assessments showing excellent agreement with benchmarks in the literature.