On a new interpretation of the classical Maxwell model

Recently, [Rao, I.J., Rajagopal, K.R., 2007. Status of the K-BKZ model within the framework of materials with multiple natural configurations. Journal of Non-Newtonian Fluid Mechanics, 141, 79–84] showed that the K-BKZ Model is a special sub-class of models based on a thermodynamic framework that takes into account the fact that bodies are capable of existing stress free in multiple configurations with special choices being made for the way in which the body stores energy and the way it dissipates energy. They also showed that several generalizations of the K-BKZ model are possible. In this short note we show that two distinct methods of storing energy and dissipating energy lead to the classical Maxwell model. That is, in addition to the classical choice for the storage of energy and rate of dissipation (the usual spring dashpot analogy) a more complicated choice also leads to the same model. This result is rather important as it shows that a variety of means for storing and dissipating energy can lead to the same mechanical response, when one restricts oneself to purely mechanical considerations.