Fatigue Simulation Of Rubber Bushing Based On Road Test Load

Rubber bushing is bearing the impact force from the suspension in the course of the vehicle and it will occur fatigue failure at low load, it will seriously influence the vehicle NVH performance once the rubber bushing was damaged. Therefore, it is of great practical value to predict the life of rubber parts in the new product development stage. This paper mainly research on the life prediction of the control arm rear bushing of a certain model, the main research contents are as follows:(1) Firstly, according to the experimental data respectively to maximum principal strain, maximum principal stress and strain energy density for the fatigue damage parameter established the rubber material fatigue life prediction model. Secondly, the results showed that three kinds of damage parameters can be very good with power law established between damage parameter and fatigue life relationship, which established according to the maximum principal strain damage parameter of life prediction model effect best and the fatigue characteristic parameter value of the rubber material is determined. It lays the foundation for the following life prediction.(2) Application of 3D software to establish three-dimensional model of the rubber bushing and carries on the grid division, bench test under the condition of strain response is calculated by using the finite element software. Subsequently, using the commercial software Ansys nCode to predict the fatigue life of the bushing bench test conditions. Subsequently, using commercial software Ansys nCode bushing bench test conditions of fatigue life prediction, And analysis the damage parameters, load and phase response superposition key issues impact on life prediction. The results of the analysis show that the damage parameters of component fatigue life has certain effect but little impact, but multiaxial load combinations of the phase difference has a great influence on the fatigue life.(3) Counting process of the random load spectrum of the ball pin after the initial treatment using rain flow counting method. Additionally, based on statistical theory,the distributions of amplitude and mean are found to confirm with normal distribution and Weibull distribution, they are independent of each other. Then the density function of the ratio of the road cyclic loading establish more complex probability based on road conditions. And the two-dimension load spectrum of a complete cycle was compiled. Furthermore, center fluctuation method is applied to get 1D program load provides a foundation load for the fifth chapter rubber bushing load transformation and fatigue life prediction.(4) In order to make the rubber bushing life prediction more accurate results, in this paper according to the experimentally measured bushing stiffness data usingnonlinear equation of the ball pin load spectra are transformed as the liner load spectrum. Combined with the strain response of rubber bushing under test conditions,the fatigue life prediction model and linear fatigue cumulative damage theory has worked out the test under the condition of bushing fatigue life. The calculated results show that the error between the predicted results and the experimental results is within the allowable range.