橡胶动态生热数值模拟与实验研究

Numerical Simulation and Experimental Study on Dynamic Heat Build-up of Rubber

为提高橡胶动态生热数值模拟的计算精度,基于时温等效原理给出了一种同时考虑温度和应变率来确定拉伸测试条件的方法,它可同时满足设备测试条件和制品使用工况.此外,为获得更准确的超弹性本构方程参数,采用了一种用应力松弛实验得到橡胶完全松弛状态下的一组应力来拟合黏弹性算法中超弹性部分的方法.采用上述测试方法并借助ABAQUS软件建立橡胶圆柱的动态生热有限元模型,在考虑温度、应变率和动应变幅值对橡胶力学性能影响的基础上,本研究用基于损耗角正切和超弹性模型的生热计算方法和基于频域Prony级数的黏弹性生热计算方法分别计算了橡胶圆柱的压缩生热.结果表明,2种方法计算的温升均与压缩生热实验结果吻合较好,但黏弹性算法精度更高,预测的升温历程与实验结果吻合很好,更好地描述了橡胶滞后生热现象,从而验证了本文提出的确定材料测试条件方法的正确性.

In order to improve the calculation accuracy of the numerical simulation of rubber dynamic heat build up,based on the time-temperature equivalence principle,a new method to determine the tensile test conditions taking into account both temperature and strain rate is proposed in this study.It may meet the test conditions of equipment and service conditions of rubber products at the same time.Moreover,in order to obtain more accurate parameters of the hyperelastic constitutive equation,a set of stresses obtained by stress relaxation experiment under the fully relaxed state of rubber is used to fit the hyperelastic model of viscoelastic approach.Based on the mentioned test methods and ABAQUS software,the dynamic compression heat generation finite element models of rubber cylinder are established.Considering the influence of temperature,strain rate and dynamic strain amplitude on the mechanical properties of rubber,the heat build-up calculation method based on loss tangent and hyperelastic model and viscoelastic heat build-up calculation method based on Prony series in frequency domain are respectively used to calculate the compression heat build-up of rubber cylinder.The results show that the temperature rise calculated by the two approaches are in agreement with the experimental results of compression heat build-up,but the viscoelasticity algorithm has higher accuracy,and the heat build-up history predicted agrees well with the experimental results,which can better describe the hysteresis heat build-up phenomenon of rubber,consequently verifying the correctness of the material test conditions proposed in this study.