Cosserat continuum modelling of chiral scale-size effects and their influence on effective constitutive laws

We derive effective models from heterogeneous Cosserat media using asymptotic homogenization and taking intoaccount size effects observed experimentally. The classification of the effective equations depends on the hier-archy of four characteristic lengths: the size of the heterogeneities ℓ, the Cosserat intrinsic lengths of the con-stituents ℓcoss and ℓchiral, and the overall characteristic length of the domain L. Depending on the different scaleinteractions between ℓcoss, ℓchiral, ℓ, and L we obtain either an effective Cauchy continuum or an effectiveCosserat continuum with or without centrosymmetry. Herewith, we extend the work of Forest, Pradel, and Sab(Int. J. Solids Structures 38 (26–27): 4585–4608 ’01) by accounting for chiral effects.