| Fundamental theories and the dynamic behaviors of electrostrictive shell structures are studied in this research. Due to the natural characteristics of electrostrictive materials, which are the electromechanical coupling relations and the actuating abilities, electrostrictive materials belong to one of the active materials categories. The shell structures are assumed to be linear and elastic, and the electrostrictive materials behave according to the Gibbs energy function. The actuating performance of electrostrictive materials is superior compared to piezoelectric materials, since the strain of the electrostrictive materials is proportional to the square of the applied electric field. Thus, the behaviors of the piezoelectric materials are constantly used as references or as comparisons to the behaviors of the electrostrictive materials being evaluated.; A general theoretical model is developed in detailing the micro-electromechanical and dynamics behavior of electrostrictive shells. The generic mathematical models and permissible boundary conditions of electrostrictive shells are based on Hamilton's principle, elasticity theory, electrostrictive constitutive relations and Gibbs energy function. A triclinic point group is utilized to derive a generic electrostrictive thick and thin shell. Furthermore, the general theoretical model is simplified to an electrostrictive thin shell with neglected shear strains utilizing Love's assumptions and material symmetries, which exhibits cubic crystal symmetry (point group m3m) properties. Moreover, polymeric electrostrictive materials are assumed to be isotropic in this study. All electrostrictive shell models have explicit derivations of mechanical membrane and bending forces, electrical membrane and bending forces and boundary conditions. The natural frequencies and the control capabilities and performances are studied based on the shell models. Moreover, sensors being used in this research are piezoelectric polyvinylidene fluoride (PVDF), and a closed-loop control of the shell model is studied in the conclusion of the investigation. |
