Two-Continuum Mechanics of Dielectrics as the Basis of the Theory of Piezoelectricity and Electrostriction

A new principle for constructing the theory of coupled dynamic electroelasticity of dielectrics that have piezoelectric and electrostrictive effects is expounded. This theory is based on the purely mechanical two-continuum description of the deformation of dielectrics as a mixture of positive and negative charges coupled into pairs neutral molecules or elementary cells provided that an elastic potential exists and the partial stresses are in linear quadratic relationship with the difference of displacements of charges. Based on the definition of the vector of polarization of an elementary dielectric macrovolume and the electric field generated by it, the equations of two-continuum mechanics are transformed into coupled dynamic equations for the macrodisplacements of neutral molecules and electric-field strength that describe the piezoelectric and electrostrictive effects. Maxwell’s equations follow from these equations as a particular case.