| An approach to the modelling of the dynamic behavior of selected polycrystalline solids is presented. The approach is applied to model the heterogeneous plastic flow, viscous processes, thermal processes and nonequilibrium phase transition of metallic projectile materials like steel under high-strain rate conditions. Another application area is to model the linear dissipation (including mechanical, dielectric and piezoelectric dissipation) of piezoceramic materials, and nonlinear hysteresis of piezoceramic materials.; The foundation of the modeling approach includes a development of a hybrid nonequilibrium thermodynamic framework that combines the concepts of internal variables and thermodynamic fluxes ( extended irreversible thermodynamics). A generalized continuum framework is used to accommodate the incompatible material manifolds by using a mixture theory. The first step of the modelling procedure is to identify internal state variables and thermodynamic fluxes (or extended state variables) from underlying physical processes. The associated constitutive models are constructed either by a deterministic or a statistical method. The restrictions on these constitutive models, imposed by the second law of thermodynamics and the principle of material frame indifference, are investigated. The complete formulation contains the derivation of the balance equations and the derivation of the nonequilibrium state functions.; Analytical and numerical tools, using perturbation techniques and finite difference techniques, are formulated to analyze selected problems. These case studies are used to analyze the developed models, provide guidance to the experimental measurements, and develop the measurement techniques for the newly introduced material parameters.; By removing the electromechanical coupling in piezoelectric ceramics, a damping model of structural solid materials is easily obtained. The developed mixture theory and the phase transition model are modified and extended to analyze the chemical reactions of a mixture of multiple species in a nonequilibrium thermodynamic framework. |
