THERMOMECHANICS OF HETEROGENEOUS MATERIALS WITH WEAKLY NONLOCAL MICROSTRUCTURE

Abstract

A unified thermomechanical framework is presented for the theory of mechanically elastic materials the physical description of which requires the consideration of additional variables of state and of their gradients (weak nonlocality). This includes both the case of additional degrees of freedom carrying their own inertia and the case of diffusiw internal variables of state. In view of practical applications to fracture and propagation of phasetransition fronts. special attention is paid to the construction and immediate consequences of the equations of balance of canonical momentum (on the material manifold) and energy at regular points and at jump discontinuities. In particular. the general expression of the dissipation at, and of the driving force acting on. phase-transition fronts is formally obtained in such a broad framework. Brief applications include thermoelastic conductors (e.g. shape-memory alloys) and elastic ferromagnets in which both spin inertia and ferromagnetic exchange forces (magnetic ordering) are taken into account.