Fatigue Life Analysis Of Rubber Bushing

The automotive chassis bushing is usually made from rubber materials.It is an important part connecting the chassis and the body parts,and its quality has a direct impact on the comfort of a vehicle.In order to improve the database of rubber materials and shorten the development period of rubber bushings,this paper studied the impact of different hardness and frequency conditions on the rubber materials and prediction methods.Based on the rubber fatigue crack nucleation approach,this paper studied the measurement and prediction of the fatigue life of automobile chassis bushings.The main research work in this paper is as follows:(1)Rubber formula B50,B55,B60,B65 were selected as different hardness rubber materials,and dumbbell specimens of the fatigue test to obtain the curve.(2)Using the method of mathematical statistics,Grubbs test,Dixon test,and Nair test to ensure that the test can reflect the fatigue life of the measured data objectively.(3)Prediction life models,which used the maximum principal engineering strain,the maximum principal logarithmic strain,the maximum principal Green-Lagrange strain and the octahedral shear strain as damage parameters respectively,were established with the prediction accuracy of 0.9 or above.And the prediction model with the maximum of principal logarithmic strain as the damage parameter had higher prediction accuracy.(4)To predict the fatigue of rubber bushings,the maximum principal logarithm strain were used as the damage parameter to establish the prediction model.The results showed that the predicted life is within 2 times of the measured lifetime,and it has good prediction effect near the diagonal line.(5)At the same time,the fatigue test of 1hz,5hz,11 hz dumbbell cylindrical specimens were carried out and the prediction model were established with the maximum principal logarithmic strain as the damage parameter.The fatigue life of the dumbbell-shaped test column is predicted to be within 2 times of the measured lifetime,and the prediction result was good.