Predicting the Dynamic Behaviour of Hydrobushings

Abstract

A novel and promising approach for the prediction of the dynamic stiffness of hydrobushings is presented, combining Finite Element and CFD methods. The rubber structure of the mount is modelled in ABAQUS and the flow of fluid through the inertia track is calculated in FLUENT. The obtained results from the latter simulation are incorporated in the finite element code for the final stiffness prediction. The calculation is very sensitive to both rubber and fluid properties. The dynamic behaviour of rubber material has accurately been characterised with a new simple shear specimen in a forced non-resonant test.Satisfactory results are obtained when comparing numerical simulations to experimental tests in a practical application. Discrepancies between simulations and tests are mainly due to the simplifications assumed when creating the model. Nevertheless, stiffness of the mount is well predicted and so is the damping, although the frequency at which its maximum value is achieved is underestimated by 4–6 Hz, result that could be improved if non-stationary boundary conditions were considered when solving the fluid flow and incorporating it to the finite element code.