Investigation On Dynamic And Static Characteristics Of Automotive Rubber Isolators And Optimization Design

Automotive rubber isolators are the key components of the isolation systems.Their dynamic and static characteristics directly affect the property of vibrationisolation. Therefore, it is very meaningful for improving their property of vibrationisolation to research on their dynamic and static characteristics.Rubber is the primary material of automotive rubber isolators. Researching onrubber mechanical characters is the basis of analyzing dynamic and staticcharacteristics of the hanger isolator.First of all, the rubber properties were summarized. The stress and strain dataof the rubber’s transformation was measured by materials testing machine, and thesuitable hyperelastic constitutive models were selected. And then, the Least SquareMethod was applied to determine the parameters of the selected constitutive model.The method of Frequency Response Function was applied to determine theparameters of viscoelastic constitutive models, and the experiment device ofmeasuring the parameters was designed.For another, the theory of vibration isolation and performance requirementwere analyzed. The hanger isolator of automotive exhaust system was takenexample to measure dynamic and static characteristics of automotive rubberisolators. The excitation signal frequency which caused the vibration of the exhaustsystem was analyzed and the dynamic and static parameters of the hanger isolatorwere measured by elastomer testing machine. The measured results could be takenas a basis of calculating dynamic and static characteristics of the rubber isolatorswith Finite Element Method.Furthermore, the method and process of calculating dynamic and staticcharacteristics of the rubber isolators were put forward. The dynamic and staticcharacteristics of the hanger isolator were simulated by Finite Element Code. Thethree directions static stiffness of the hanger isolator was calculated, and thedynamic parameters were calculated by the software under sine excitation signal.The error was very small. Four types of excitation signal were used to investigatethe external factors (excitation frequency, amplitude and pre-load) whichinfluenced on the dynamic characteristics of the hanger isolator. Finally, thestructure of the hanger isolator was optimized in the orthogonal experiment, and the great influencing structural parameters were found. An optimization programwas provided and it achieved the desired effect.It may better understand the theory of vibration isolation that investigation ondynamic and static characteristics of automotive rubber isolators and optimizationdesign, and it will guide to design the high-performance rubber isolators.