PSEUDOMOMENTUM AND MATERIAL FORCES IN INHOMOGENEOUS MATERIALS - (APPLICATION TO THE FRACTURE OF ELECTROMAGNETIC MATERIALS IN ELECTROMAGNETOELASTIC FIELDS)

The balance of pseudomomentum (covariant material, canonical momentum) is established in different ways for both pure finite-strain anisotropic elasticity and electromagnetoelasticity in the Galilean approximation for materially inhomogeneous solids. This balance law relates pseudomomentum, Eshelby's energy-momentum tensor, and the material inhomogeneity force. The relationship with the Hamiltonian canonical formulation of finite-strain elasticity is outlined and consequences for the evaluation of energy release rate via path-independent integrals in electro- or magnetoelasticity are drawn. This work, of a fairly general nature, builds on the pioneering results of the Stanford group around G. Herrmann.