The thermodynamic restrictions for elastic-viscoplastic material models with evolution equations for the internal variables involving rates of external variables are derived. Compatibility with the Clausius-Duhem entropy inequality (Second Law) is required and this yields non-classical potential relations and a residual dissipation inequality.For two viscoplastic models (Robinson et al., Krempl et al.), which involve external variable rates in the evolution equations and which have not been embedded in a thermodynamic frame, the consistence with the non-classical potential relations is discussed. Further, the evaluation of the residual dissipation inequality is done for a thermodynamic extension of an early version of the Robinson model. Necessary and sufficient conditions for the material data are obtained to insure a non-negative mechanical dissipation. The results demonstrate that the model is formally consistent with the Second Law.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.