Mehrdad Nasirshoaibi - Faculty of Mechanical Engineering, Azad University of Parand, Tehran, Iran
Nader Mohammadi - Faculty of Mechanical Engineering, Azad University of Parand, Tehran, Iran
Hamid Dehghan - Faculty of Mechanical Engineering, Azad University of Parand, Tehran, Iran
Masih Nasirshoaibi - Faculty of Mechanical Engineering, Azad University of Semnan, Semnan, Iran

The equations of forced vibration of a Timoshenko double-beam system that continuously joined by a Pasternak layer under compressive axial loading are considered in this paper. Based on the Timoshenko beam theory, deflections of the beams are shown and the general solutions of forced vibrations of beams subjected to arbitrarily distributed continuous loads are found. The analytical solution of forced vibration with associated amplitude ratios is determined. The dynamic responses of the system caused by arbitrarily distributed continuous loads are obtained. Vibrations caused by the harmonic exciting forces are discussed, and conditions of resonance and dynamic vibration absorption are formulated. The effects of Pasternak layer on the forced vibrations of the Timoshenko double-beam system are discussed for one case of particular excitation loading. Numerical results of the present method are verified by comparing with those available in the literature. The important result that this paper put emphasize on it is that base on Timoshenko theory which takes into account the effects of shear deformation and rotary inertia Pasternak layer doesn’t have any considerable effect on the magnitudes of the steady-state vibration amplitudes. Thus the Timoshenko beam-type dynamic absorber with Pasternak layer acts as like as Winkler elastic layer just with a little more efficiency.

Forced vibration, Timoshenko double-beam, Compressive axial load, Pasternak layer