Forced vibration analysis of Timoshenko double-beam system under compressive axial load by means of Green's functions

As typical and significant structural elements, double-beam systems widely exist in practical engineering applications such as some subgrades and highway bridges. This paper focuses on presenting the closed-form solutions of the forced transverse vibration of a coupled Timoshenko double-beam system under compressive axial load. The solutions are generalized and can be suitable for any boundary conditions. The present model is generalized and can be reduced to any existing double-beam systems. Timoshenko model is employed to express the two beams of the double -beam system. Using the Laplace transform, the steady-state Green's functions of the coupled double-beam system can be derived. Since the Green's functions are fundamental solutions of the system, the steadystate forced vibration solutions can be obtained with the help of the superposition principle. In the numerical section, the present solutions are compared with the other known results along with FEM solutions for verification. In addition to the influences of the stiffness modulus of Winkler elastic layer and axial force on the present solutions that should be discussed, the influences of some physical parameters, such as the height-to length ratio, external frequency, shearing effect, rotational inertia, on the closed -form solutions will also be presented. The effect of the compressive axial load is studied in this work. (C) 2019 Elsevier Ltd. All rights reserved.