Research On The Accelerated Fatigue Test Method For Rubber Isolator

Rubber isolators are widely used in automotive vibration isolation systems. Bench test under random load is the reliable method to prove fatigue strength of a rubber isolator. However, it needs a large number of time when putting the whole load data into test. Thus, how to decrease fatigue test period has great significance in shortening development cycle and saving fund. It's also the hot research project in the automotive OEMs and parts suppliers.The contents of this dissertation are:(1) The solution of dynamic stiffness is displaced with that of static stiffness based on the analysis of dynamic-static characteristics of a rubber isolator, considering the difficulty in computing dynamic stiffness of a rubber isolator owing to the real-time variation of road load spectrum. And the relation of dynamic-static ratio is established experimentally for filled rubber material.(2) The method to predict the life of a rubber isolator is analyzed. The maximum principal strain is selected as an evaluation parameter. And the relation of strain-life is obtained experimentally for filled rubber material to make it possible to predict the life of a rubber isolator under different load cases.(3) According to the Miner linear cumulative rule and the damage equivalent principle, the method of editing accelerated fatigue test spectrum is studied and an engine mount (rubber isolator) is taken as an example to show the whole editing process. It is shown that the uniaxial accelerated spectrum edited with the proposed method is effective in uniaxial accelerated fatigue test of rubber isolator and the test time is cut down for 95.5%.(4) Considering the phase correlation of rubber isolator's axial loads, the method to edit multiaxial accelerated fatigue test spectrum is studied primarily.