<p>A mathematical model of a piezofiber composite disk (FibrCD) actuator in the form of a circular coil of a piezoelectric single-core cable with radial polarization of the piezoelectric layer between the core and the shielding electrodated coating was developed; cable turns are attached to each other with a polymer binder (matrix) to form a monolithic piezoelectric FibrCD-actuator. The desired analytical solutions for effective coefficients of piezoelectric linear expansion of the FibrCD actuator were obtained on the basis of an exact solution of the coupled boundary value problem of electroelasticity for a cylindrical composite cell “piezocable/epoxide” with an infinitesimal thickness, which causes a plane stressed state using a polydisperse model of a real fibrous structure. The cylindrical piezoelectric layer of the cable has transversally isotropic elastic and electrical properties with radial orientation of the symmetry axis; the properties of the cable core and epoxy binder are isotropic. Control voltage is applying to the core at zero electric potential on shielding surface electrode of the cable, which causes deforms the piezoelectric layer between electrodes at a given value of radial displacement or stress on the outer surface of the polymer (epoxide) layer of the cell. The effective piezoelectric characteristics of the FibrCD-actuator were calculated and numerically analyzed at various values of its structural parameters, in particular, at various of the thickness of the piezoelectric layer.</p>