橡胶弹性元件低温刚度预测方法

The Method of Stiffness Prediction of Rubber Elastic Elements in Low Temperature

在20,0,-10,-20,-30,-40℃下,对橡胶材料进行单轴拉伸试验,采用4种常用类型本构模型拟合试验数据,得出不同温度下的模型参数,并利用拟合优度对模型拟合效果进行评估,结果表明Ogden3和4阶模型拟合效果最好。分别考虑环境温度以及温度场的改变(从室温20℃逐步降低至-40℃)对橡胶力学性能的影响,对锥形橡胶弹簧在各试验温度下施加垂向载荷的刚度进行预测,并对产品进行相应的刚度试验。试验结果表明,仿真分析中若考虑温度场的改变对橡胶力学性能的影响,刚度预测精度显著提高;在环境温度低于-20℃时,仿真分析有必要考虑温度场的变化而产生的热应力对橡胶弹性元件刚度的影响。

Uniaxial tensile tests were conducted on rubber materials at the temperatures of 20, 0,-10,-20,-30 ℃ and-40 ℃. The test data were fitted with four common hyperelastic constitutive models, the constitutive model parameters at different temperatures were obtained, and the fit goodness were used to evaluate the fitting effects of the models. The results show that Ogden（N=3, N=4） models have better fitting effects. The impacts of ambient temperature and the change of the temperature field（from room temperature 20 ℃ reducing to-40 ℃ gradually） on mechanical property of rubber materials were considered, the stiffness prediction of cone-shape spring under perpendicular loads were conducted at various testing temperatures, and the corresponding stiffness tests were made on products. The test results show that the stiffness prediction accuracy has a significantly increasing if the impact of the temperature field change on mechanical property of rubber materials was considered in simulation analysis. At the the ambient temperature less than-20 ℃, it is necessary to consider the impact of thermal stress in the temperature field change on the stiffness prediction of rubber spring in simulation analysis.