Forced Vibration Analysis of Viscoelastic Beam Subjected to a Suddenly Applied Moving Harmonic Force and Moving Mass Flow

In present study, dynamic response of viscoelastic beams subjected to moving harmonic loads and mass flow is investigated. A semi-analytical solution composed of the Galerkin and fourth order Runge-Kutta methods is adopted to solve the governing equation of motion. The results of this analysis are obtained for four different boundary conditions, namely pinned-pinned, fixed- fixed, fixed- pinned and fixed- free. The moving force is assumed to move with accelerating, decelerating and constant velocity types of motion and the mass flow has a constant velocity. The beam is assumed to be initially straight and the applied harmonic force and mass flow pass suddenly over the beam. Then, the effect of simultaneous and non-simultaneous application of harmonic force and moving mass on the dynamic beam response is investigated. It should be noted that the effect of force is removed after crossing the beam. In the present work, the effects of various parameters such as mass ratio, various types of motions, effect of applying force and mass flow and effects of various boundary conditions on the dynamic displacement of the beam are elucidated. Without mass flow, results are compared with the data in the previous researches and a good agreement is achieved. Also, for another comparison, the results of deflection presented here are compared with the generalized differential quadrature method and excellent agreement is obtained.