Finite Element Analysis of Static Elastic Characteristics of the Rubber Isolators in Automotive Dynamic Systems

A Finite Element Analysis (FEA) of the static elastic characteristics of rubber isolators in automotive dynamic systems, such as suspension bushings and rubber springs of hydraulic engine mount, is carried out. The basic theory for the finite element analysis of rubber components is reviewed, and the method for conducting experiments for hyperelastic material constitutive model is studied. The specific requirement of the element for rubber FEA is also stated. As a case for studies, the stiffnesses of a complex rubber bushing subjected to radial, axial, torsional or tilting loading are calculated by Finite Element Method (FEM) and some closed form formulae based on regular bushing configuration. The results are compared with the experimental data. It is found that the FEM simulation results agree well with the experimental data. However, only one analytical formulation about the radial stiffness can give results close to the test data, and the predictions given by the other closed form solutions are far away from experimental results. As another case for studies, FEA on a rubber spring of a hydraulic engine mount is carried out to calculate the stiffnesses in three perpendicular directions. The results are also in good agreement with experimental data. This research demonstrate that the FEA method is effective for the static characteristic prediction of rubber components, and that FEA can play an important role in the design of rubber isolators.