Textile architecture–anisotropy coupling in natural hybrid woven composites: A comprehensive multiscale modelling framework

The prediction of effective elastic properties of natural hybrid woven composites (NHWCs) is challenging because of the coupled effect of the fiber hybridization, weave architecture and multiscale fiber–matrix interactions. This work proposes a hierarchical two-step finite-element homogenization method for two different architectures of flax–basalt/epoxy NHWCs: a yarn-level representative volume element with periodic boundary conditions and voxel-based mesoscale woven unit cells of plain and 2 × 2 twill architectures. Yarn level properties show close agreement to Chamis, Mori–Tanaka (MT), Multiscale Designer (MSD), Mechanics of Structure Genome (MSG) and Digimat-FE within 1–3%, and fabric level properties are able to reproduce experimental twill stiffness within 3–7%. Parametric analyses demonstrate that the wider yarn and higher composite fibre volume fraction are more effective in increasing the axial modulus and shear moduli while higher yarn spacing and fabric thickness are more effective in decreasing the in-plane stiffness through crimp-amplified matrix participation. Twill weaves show superior stiffness compared with plain weaves, due to less yarn crimp and longer float lengths that promote more efficient load transfer. The fully resolved structural response is replicated with 3–7% variation at a 57-fold element reduction. The main conclusion is that weave architecture and hybridization approach control the anisotropic stiffness of NHWC. The extensions to the framework involve uncertainty quantification, progressive damage, and hygromechanical coupling.