温度影响下炭黑增强橡胶复合材料的循环拉伸力学行为

Temperature effect on the mechanical behavior of carbon black reinforced rubber composites under cyclic tensile loadings

为研究温度变化与炭黑增强对橡胶复合材料循环拉伸力学行为的影响,利用含温度箱的非接触式自动网格法测试系统,对4种不同炭黑含量的填充橡胶开展了不同温度下的阶梯式加卸载拉伸力学实验。实验结果表明,在各个循环段,炭黑填料对橡胶基体的增强效应都随温度升高而减弱,且温度越高,增强效应的减弱趋势越平缓,这是导致填充橡胶循环拉伸力学行为及温度相关性比天然橡胶更为复杂的根本原因;同时,橡胶材料在各个循环阶段的平衡迟滞损耗都随炭黑含量呈非线性递增,且这种迟滞损耗随炭黑含量递增的趋势受温升影响而减弱;最后,通过对不同温度和不同循环次数的实验结果作比较发现,经调制预处理后的增强橡胶Mullins效应几乎不受环境温度和炭黑增强的影响,这一点与无变形历史的未调制橡胶有很大的不同。

In order to investigate the effects of temperature variation and carbon black(CB)reinforcement on the cyclic tensile behavior of rubber composites,four kinds of elastomers filled with different CB contents are experimentally studied at different temperatures,based on cyclic loading-unloading tests accomplished by employing a non-contact Automatic Grid Method system containing a heat oven.The results indicate that the enhancement effect of CB filler upon rubber matrix gradually decreases with temperature rising,which leads to the reduction of mechanical properties during each cycle.It subsequently makes the cyclic tensile and temperature dependent behavior of filled rubbers more complicated than the pure rubber which does not involve any CB reinforcement.In the meantime,the equilibrium hysteresis loss of rubber material during each cycle represents the non-linear increase along with the amount of CB filler,and this changing trend is also significantly influenced by the temperature elevation.Finally,by comparing the deformation energies for all loading steps,it can be concluded that their Mullins effect is nearly independent of environmental temperature and CB particle reinforcement,since the rubber specimens have been pre-conditioned.