Internal stresses in the electrostriction phenomenon viewed through dynamic mechanical analysis studies conducted under electric field

Abstract

A model for studying the mechanical internal stresses into dielectric materials is developed in the present work. The model takes into account the formalism of inclusions in continuous media. The dielectric material is assumed to be partitioned in different cubes which form a sizeable bulk material in such a way that a given cube can be of the dipolar phase and its neighbor can be of the same phase or the matrix. The behavior of the internal stresses promoted by the electrostriction phenomenon can be monitored by studying the behavior of both the misfit coefficient related to the strain misfit and the transfer of elastic energy process. The equations obtained through the here presented model are calculable using magnitudes from mechanical tests, in particular dynamic mechanical analysis, which is very sensitive to changes in the microstructure. Dynamic mechanical analysis as a function of the electric field is reported, perhaps for the first time in literature, for the study of dielectric materials, giving rise to a useful tool for studying the behavior of internal stresses in dielectric materials.