Research On The Dynamic Mechanical Properties Of Tire Rubber Based On The Finite Element Analysis Technique

Rubber test is one of the necessary preconditions for the production of tire rubber. The uni-axial tensile test, uni-axial compression test, bi-axial tensile test and plane shear test are commonly used among the tests of tire rubber, but the above testing means can not accurately predict the performance of tire rubber under dynamic load. Therefore, the dynamic mechanical thermal analyzer is chosen as one of main means of tire quality prediction, especially the tire rubber properties by the most leading tire manufacturers. Dynamic thermal mechanical analyzer has the advantages of wide testing frequency range, reliable test data, short test period, etc.Dynamic mechanical properties of tire rubber based on dynamic mechanical thermal analyzer and ABAQUS are studied in this paper. The influencing factors of hyper-elastic properties of tire rubber are analyzed under dynamic shear load in order to determine the test scheme of the hyper-elastic properties of tire rubber. The accuracy of the test data prediction is compared under different hyper-elastic models, and the model with higher accuracy is optimized under the dynamic shear load. Based on the viscoelastic properties of the tire rubber, the influence factors of the viscoelastic test under the dynamic shear loading condition are analyzed, and the test scheme of the viscoelastic properties of tire rubber is determined. The viscoelastic master curves are constructed according to the test results. The viscoelastic mechanics parameters are calculated by using the mathematical software MATLAB through the analysis of different parameter settings. The main research results are as follows:(1) The hyper-elastic model with higher accuracy of the test data is optimized. Based on stress-strain measurement model of the dynamic thermal mechanical analyzer, the influencing factors of the test of hyper-elastic properties were analyzed in order to determine the hyper-elastic rubber test scheme. Based on the analysis of the hyper-elastic properties of tire rubber, the calculation formula of the hyper-elastic parameters is determined by the matching of the hyper-elastic constitutive model and the load pattern. The accuracy of dynamic shear test data prediction is analyzed by MATLAB. Based on the comparison and analysis of the accuracy, the calculation model of the hyper-elastic parameters of tire rubber is optimized.(2) The test scheme for the viscoelastic properties of the tire rubber is designed to form the viscoelastic master curve. In the process of designing the test, the effect of frequency and temperature on the test results is mainly discussed. The analysis shows that with the rise of the temperature, the values of modulus decrease, and the smaller the temperature interval, the smoother the modulus curve. The energy storage modulus and loss modulus show a uptrend with the increase of the frequency. The composite modulus curve decreased greatly in the low temperature region than that in the high temperature zone, when the temperature increases with the same amount, and different temperature interval has certain influence on the accuracy of the viscoelastic master curves. From this point of view, the viscoelastic test schemes are determined according to the above analysis. The viscoelastic master curves used to calculated viscoelastic mechanics parameters are determined through the shift factor analysis of different calculation methods.(3) Rubber viscoelastic parameters are analyzed based on the MATLAB software and dynamic shear test data. The model of viscoelastic mechanics applied to the finite element analysis is selected, and the objective function is formed by the least square method to solve the dynamic viscoelastic parameters of the tire rubber. The influence of relaxation time sequence, the number of moving units and frequency conditions on the calculation results is analyzed, and the calculation results show that the value of the relaxation modulus grows down with the increase of the number of movement units under the first relaxation time sequence, when the range of relaxation time. The relaxation modulus decreases with the rise of the relaxation time or the number of moving units, and the initial value of relaxation modulus of different number of movement units grows down under the second relaxation time series. The calculation results of the two relaxation time sequences has a perfect agreement according to the first and second kind of relaxation time sequence of the viscoelastic parameter calculation results. When second kinds of relaxation time series are used to solve the viscoelastic parameters of the tire rubber, the number of the moving unit is at least 9 to describe the performance of the material accurately. When the frequency range is 1-60Hz, the curve of the decline rate and the inflection point is more close to the viscoelastic parameters of the general law of change. The calculated viscoelastic and hyper-elastic parameters are combined to be used in the finite element analysis, and the application of the research content is demonstrated.