COMPUTATIONAL METHOD FOR THE DYNAMIC PROPERTIES OF RUBBER ISOLATORS

To predict the dynamic properties of rubber isolators, a nonlinear viscoelastic model consisting of the Mooney-Rivlin model and multiple Maxwell models is proposed in this paper. The method of fitting the viscoelastic parameters in the time domain and frequency domain is given. Using the estimated model parameters and the developed finite element model, the dynamic characteristics of a rubber mount are calculated and compared with experimental results. In addition, we set up an equivalent mechanical model of the dynamic stiffness of rubber isolators and analyze the difference between the original point dynamic stiffness and the cross-point dynamic stiffness. The results show that the influence of the additional inertia force in the test can be eliminated by using the cross-point dynamic test method, which is suitable for the test of the dynamic characteristics of the rubber isolators. Meanwhile, a finite element model of rubber isolators is built to analyze the cross-point dynamic stiffness and original point dynamic stiffness. The analysis results are compared with the experimental results to verify the correctness of the finite element model and the mechanical model. The advantages and disadvantages of three methods for fitting the viscoelastic parameters in the time domain (relaxation and creep) and frequency domain (simple harmonic dynamic test) are analyzed.