Vibration analysis of vehicle system with hydraulic mount using a lumped parameter model

Abstract

A lumped mass-spring-dashpot model is often used for hydraulic mount for vibration analyses of vehicle. However, it was verified that the model can be justified only when bottom of the hydraulic mount is fixed. In order to supplement shortcomings of the model, a hydraulic model was developed in case that top- and bottom-sides of the mount vibrate. Nevertheless, it is still not possible to perform the modal analysis considering the degree of freedom due to fluid in hydraulic mount by using the existing hydraulic model because it contains only the force component. Therefore, in this study, a new method for modal analysis with hydraulic model using an additional displacement is proposed to consider the degree of freedom due to the fluid. It is experimentally verified that frequency-dependent characteristics of the hydraulic mount generates an additional mode occurring in the frequency range related to ride comfort. In addition, the vibration characteristics of additional mode related to powertrain in vehicle system, which hasn't been studied in the previous literatures, is examined through parameter studies. The present model is compared with the lumped mass-spring-dashpot model from the viewpoint of dynamic response for the different types of base excitation