Electroelasticity of Disc Piezofibrous Actuator

A microstructural model of a coil composite piezoelectric fiber disk (FibrCD) actuator has been developed. The actuator is formed by winding a large number of turns of a thin electroded piezoelectric fiber in the form of a shielded single-core cable with a radially polarized piezoelectric interelectrode layer, followed by impregnation and continualization of the turns with a polymer binder. An exact analytical solution has been obtained for the electric and deformation fields of the axisymmetric coupled boundary value problem of electroelasticity on the elementary composite cell “piezoelectric cable/binder shell.” Further, the exact solution for electroelastic fields inside a composite cell loaded with electric voltage on the cable electrodes is used to find exact analytical solutions for the tensors of effective coefficients of piezoelectric stresses and linear piezoelectric expansion (deformations) of the fiber composite as a homogeneous disk FibrCD actuator with cylindrical anisotropy within the framework of the known polydisperse model of the composite structure. The calculation and numerical analysis of the FibrCD actuator characteristics are performed for various values of its macroscopic and structural parameters, in particular, the disk (ring) thickness, the difference between the outer and inner radii of the ring, the relative sizes of the radius of the conductive core and the thickness of the binder layer between adjacent cable turns. The efficiency of the FibrCD actuator is confirmed in comparison with the characteristics of traditional actuators.