Electromechanical properties of polarized piezoelectric materials Polarized piezoelectric materials are characterized by several coefficients and relationships. In simplified form, the basic relationships between the electrical and elastic properties can be represented as follows: D: electric flux density d: piezoelectric charge coefficient T: mechanical stress εT : permittivity (for T = constant ) E electric field S:mechanical strain sE: Compliance or elasticity coefficient (for E = constant) These relationships apply only to small electrical and mechanical amplitudes, so-called small signal values. In this range, the relationships between mechanical, elastic deformation S or stress T and electrical field E or electrical flux density D are linear, and the values for the coefficients are constant. Piezoelectric Charge Coefficient, Piezoelectric Deformation Coefficient, Piezo Modulus d The piezo modulus is the ratio of induced electric ch...