Microcontinuum approach to electromagneto-elasticity in granular materials

A micromorphic theory of electromagnetic non-conducting materials is outlined accounting for microdensities of mass and bound charges. Electromagneto-elastic coupling is then described by connecting microstrain measures with electric dipoles and quadrupoles. Application of this approach to granular materials is realized by exploiting well established constitutive models of grain interactions. A set of general equations is derived from a variational approach and its linearized form is discussed under the quasi-static assumption. Electromagnetic effects, which are expected under the action of an electric field, arise due to induced polarization, assuming grains are endowed with an intrinsic electric dipole and/or quadrupole.