Dynamic Response of a Double Beam Interconnected by a Viscoelastic Layer Due to a Moving Vehicle with a Constant Acceleration

Forced vibration of a double-beam interconnected by a viscoelastic layer is investigated under two constant acceleration moving loads. These forces are standing for a vehicle rear and front axis loads; hence their values depend on the vehicle acceleration. The Euler-Bernoulli equations and Winkler model are used for the beams and the viscoelastic layer, respectively. With deriving the equations, the modal expansion and modes orthogonality are used to obtain the dynamic response of the beam. Middle point deflections of both beams are presented considering various accelerations, damping ratios and stiffness values of viscoelastic layer. The present work is validated with the results of other authors. It is observed that the damping ratio has not a considerable effect on middle point deflection of the upper beam, whereas it has a significant effect on that of the lower one. Meanwhile, increasing the stiffness leads into decreasing the effect of damping ratio in middle point of the double-beam, decreasing the deflection of the upper beam and increasing that of the lower beam. Increasing the acceleration has not any considerable effects on the general trends. In higher accelerations, increasing the stiffness will decrease the effect of damping ratio with a lower intensity.