Development Of Shock Absorber Rubber Bushing Fatigue Test System

Shock absorber rubber bushing (the following is short for rubber bushing) is a metalrubber spring which is made of rubber material and metal. It is widely used in automobilesuspension system and various kinds of support device and guiding device because it has theadvantage of good buffer, noise reduction, vibration isolation, shock resistance and absorbinghigh frequency vibration. Rubber bushing can effectively improve K&C characteristics ofautomobile suspension system and elevate vehicle ride and ride comfort. Rubber bushing inreal vehicle use condition often works under complex cyclic load, thus it is prone to fatiguefailure and results in performance deterioration and failure of shock absorber. Because rubberbushing is a highly nonlinear viscoelastic material, it is difficult to accurately study fatiguelife of rubber bushing by theoretical analysis method. It can only be studied by methods offatigue life test.Based on the development status of rubber bushing test system at home and abroad,mechanical model of rubber component is set up according to the viscoelastic properties ofrubber components. Rubber bushing fatigue test method and test specification are determined,judgment criteria of rubber bushing fatigue failure is put forward according to rubber bushingforce analysis. Based on rubber bushing force condition and real vehicle working condition,rubber bushing fatigue test system overall design scheme which consists of mechanicalsystem design scheme and control system design scheme is put forward. It provides guidanceand theoretical basis for structure design of mechanical system through power matching of thetest system. Mechanical structure design, which mainly includes excitation device, loaddevice, and test fixtures etc., is completed according to mechanical system design scheme oftest system.3D model of the test system is established after finishing the mechanical systemstructure design. And then verify the feasibility by carrying on simulation study of test system.According to the measurement and control system design scheme, the hardware selection ofdata acquisition system and software programming are finished. Finally, verify the feasibilityand reliability of test system by choosing a type of vehicle rubber bushing and conductingfatigue test. Based on the rubber bushing fatigue failure judging criteria to determine whetherit occurs fatigue failure or not.Rubber bushing fatigue test shows that excitation frequency, excitation force amplitudeand preload of rubber bushing fatigue test system are all adjusted. It can meet constant forceamplitude fatigue test requirement of various specifications of rubber bushing. After fatiguetest, the eligibility of rubber bushing is determined by adopting rubber bushing fatigue failurejudging criteria determine.