A new approach to identify hysteretic damping of a rubber isolator

In order to realize modeling and dynamic analysis of a mechanical system containing a rubber isolator, a parameter identification method of rubber hysteretic damping was investigated. Firstly, the sine vibration test of the rubber isolator was conducted so as to acquire the relationship between the resilience force and the displacement with different frequencies and amplitudes. Secondly, according to the principle of damping dissipating same energy in one vibration period, the resilience force was decomposed into spring force and damping force, which could be identified by using a new approach called variable-rate stiffness and damping parameter identification. The relationships of elasticity coefficient and damping coefficient with variation of frequency would be obtained using this parameter identification method. Then, the above mentioned parameter identification results were applied in modeling and dynamic analysis of a shaft structure including rubber isolators. A big mass method was also used in the process of calculating response acceleration curve with variation of frequency at the position of the mass centroid. The maximum acceleration reached 11.79 g at frequency of 100Hz. Finally, the sine vibration test of the whole structure was carried out and the distinctions of the test results and the calculation results were carefully compared. Experimental results indicated that the max error of the calculation results is up to 9.2%, it satisfies the requirement of engineering calculation. It proved the correctness of this parameter identification method. Furthermore, the application of this method would make the process of modeling and analysis for a rubber isolator unified and standardized.