<p>Experimental and theoretical study of the dynamic behavior of a cantilevered rod-strip, connected at points of the one front surface with a supporting element in the area of fixation of finite size, was carried out. The bending vibrations of a rod excited by an axial harmonic force applied to the end section of the fixed part were experimentally registered and modal analysis was carried out. A new refined model of the fixed section deformation was constructed. It was derived from the Timoshenko’s shear model, accounting for the transverse shear and lateral strains, condition of continuity of displacements, and the support element at the points of their connection in the fixed section. The displacements of support element were considered to be specified. The deformation of the cantilevered (unfixed) part of the rod was described by the classical Kirchhoff-Love model. The kinematic conditions of coupling of the fixed and cantilevered parts of the rod were formulated. On the basis of the Hamilton-Ostrogradsky variational principle, the equations of motion of the cantilevered and fixed parts of the rod, the boundary conditions corresponding to them, and the force conditions of conjugation of the cantilevered and fixed parts of the rod were obtained. An exact analytical solution of the problem formulated was found. Numerical experiments were conducted for two rods made of aluminum alloy D16AT and fiber composite based on carbon tape ELUR-P and binder XT-118, accounting for the flexibility of the fixed section at specified displacements of the support element in the form of a steel channel. It was established that the vibrations of the cantilever part of the considered rods at small values of their thickness compared to the length of the fixed section were almost completely determined by the specified displacements of the support element.</p>