Free vibration of connected double-beam system with general boundary conditions by a modified Fourier–Ritz method

In this paper, free vibration of connected double-beam system under general boundary conditions is investigated by a modified Fourier–Ritz approach. The effects of the restrained stiffness of the springs and the elastic layer stiffness on modal properties are incorporated in the current framework. The displacement components can be expressed as Fourier cosine series plus auxiliary polynomial functions, which aim to eliminate the discontinuities of displacement and its derivatives at both ends and to enhance the convergence of the results effectively. Numerical examples were presented and discussed for several different geometric and material properties as well as distinct boundary conditions. The effectiveness and rapid convergence of the present method can be verified from the results. Numerous new results for connected double-beam system with arbitrary boundary conditions are presented.