Dynamic deformation of solid materials is described in terms of nonuniform material motion and simultaneous thermoelastic strain and plastic flow. For deformations of arbitrary form and magnitude in an initially isotropic solid, an approximate expression for the entropy production is given, and the interrelations among the thermodynamic variables of stresses, elastic and plastic strains, and temperature and entropy are derived. The theory is specialized to plane-wave geometry, appropriate for describing a weak planar shock, and is compared with the relaxing solid model which has previously been used to analyze plane shocks in solids. A qualitative examination of the mechanics of elastic strain and plastic flow indicates that a thermodynamic description is accurate for many fast deformation processes in solids.

• Received 17 April 1979

DOI:https://doi.org/10.1103/PhysRevB.22.1477