Elastic and viscoelastic behavior of chiral materials

Chiral materials are not invariant to inversions: there is a distinction between rightand left-handed material. Material properties such as piezoelectricity and pyroelectricity, represented by tensors of odd rank, can only occur in chiral materials. Chiral e!ects in elasticity cannot be expressed within classical elasticity since the modulus tensor, which is fourth rank, is unchanged under an inversion. We consider e!ects of chirality in elastic materials described by a generalized continuum representation, speci"cally Cosserat elasticity. Analysis of several con"gurations discloses a chiral material to generate reaction moments when compressed as a slab. A chiral plate bent to hyperbolic shape is predicted to exhibit size e!ects from the Cosserat characteristic length, and a shear force from the chirality. This analysis can be used for the interpretation of experiments on compliant chiral materials, in particular the evaluation of the elastic constants. Viscoelastic chiral solids are examined in the context of the correspondence principle. ! 2001 Elsevier Science Ltd. All rights reserved.