THERMODYNAMIC RELATIONS OF NON-LINEAR ELECTRO-ELASTICITY

On the basis of the existing theories of hyperelastic dielectrics, thermodynamic relations are derived that hold for second order phenomena at the most (such as the non-linearity of Hooke's law, the dependence of elastic constants on the electric field, the electrostriction of piezoelectric materials etc.). The relations are used to estimate the relative magnitude of the new terms that arise in consequence of the finiteness of the deformations considered, in the case of one of the electron-mechanical properties of quartz. © 1969 Czechoslovak Academy of Sciences.