Linear thermoviscoelasticity. Part II: Energy balances

Based on the functional thermoviscoelastic model developed by the authors in the preceding paper of this issue, energy balances are drawn up (dissipation vs internal work production) for a material under thermomechanical loading. By classifying the thermomechanical processes involved, we show how delayed phenomena can appear on the energy balance for processes ending with an equilibrium state. Under cyclic loading, the characteristics of the energy phenomena are found to differ between the transient period and the established periodic mode. Lastly in the case of a null trace strain, methods of modelling the relaxation kernels are proposed with which it is possible to draw up energy balances of the kind using mechanical data.