<p>A refined transformational model of dynamic deformation of a strip rod consisting of a fixed and two non-fixed (cantilever) sections was constructed. It was assumed that the rod in the fixed section is connected to an absolutely rigid support element, which has no displacement of the connection points with the rod in the finite length section. To describe the process of deformation of the fixed section of the rod, an approximation of tangential displacements by a third-degree polynomial along the transverse coordinate was adopted. To describe the deflection, an approximation of tangential displacements by a polynomial of the second degree was adopted, provided that there are no displacements on the contact surfaces of the marked section with a rigid fixed support element. The movements of the points of the loose sections of the rod were described by the simplest shear model of S.P. Timoshenko. The conditions for the kinematic coupling of fixed and non-fixed sections of the rod were formulated, taking into account which, based on the D’Alembert-Lagrange variational principle, corresponding equations of motion and boundary conditions, as well as force conditions for coupling sections, were obtained for the sections introduced into consideration. Based on the constructed equations, an exact analytical solution to the problem of forced harmonic vibrations of a rod of the considered class was found. Numerical experiments have been carried out to determine the dynamic reaction during resonant vibrations of a strip rod made of a unidirectional fiber composite based on carbon fiber ELUR-P and binder XT-118. A significant transformation of normal and tangential stresses during the transition across the boundaries from the loose sections of the rod to the fixed one was shown, as well as their pronounced localization in the areas of the fixed section located near the marked boundaries.</p>