Structure, morphology and mechanical properties of Rhectophyllum camerunense (RC) plant fiber. Part II: Computational homogenization of the anisotropic elastic properties

In part I of this paper, we used statistics to derive some parameters (actual area of the cross-section, polar moment of inertia) and Voronoi partitioning techniques to reconstruct the section of a plant fiber. The reconstructed geometry is used here to perform bottom-up predictive simulations of the anisotropic elastic properties of the fiber taking into account the underlying physics at the finer scales (thicknesses of the cell wall layers, microfibril angle). For this purpose, three load cases are considered and the overall response of the fiber is computed numerically at each material point by a detailed modeling of the microstructure at the point under consideration. The predicted longitudinal modulus is in good agreement with experimental results. Moreover, computational homogenization allow us to access to the overall elastic properties of the transverse isotropic material, which is very hard to do by direct measurement due to the minute cross-section of the fiber.