A STUDY OF A TRANSMITTED FORCE FROM HARMONIC MOVING LOAD ON A BEAM SUPPORTED BY NONLINEAR VIBRATION ISOLATOR

Abstract

The force transmitted from Bernoulli–Euler beam, resting on a nonlinear vibration isolator at each end and subjected to a moving harmonic load, has been investigated in this paper. The vibration isolator consists of nonlinear spring and nonlinear damper. Assumed-mode method is used to obtain the nonlinear equations of motion. The effect of the nonlinear characteristics of spring and damper on transmissibility ratio is discussed. Also the effect of velocity of the moving load is explained.The simulation results show that the increasing of the nonlinear parameter for each spring and damper leads to reduce transmissibility ratio. Results have confirmed that it is not necessary to install nonlinear spring with nonlinear damper in order to reduce transmissibility ratio more. The vibration isolator which includes linear spring and nonlinear damper may give good isolation. For the velocity effect, the results show the velocity values of moving load have clear impact on the transmissibility ratio especially at resonance state where the increasing in velocity leads to reduce transmissibility ratio.