炭黑填充橡胶超弹性力学性能的三维有限元模拟

3D FINITE ELEMENT MODELING OF THE HYPERELASTIC MECHANICAL BEHAVIOR OF CB-FILLED RUBBER

本文采用随机序列吸附(RSA)方法建立了不同炭黑含量填充橡胶的三维随机细观代表体积单元(RVE),模型中炭黑颗粒位置随机分布,颗粒半径服从均值为32nm的正态分布.以炭黑含量17.1%的填充橡胶为例,详细探讨了确定材料细观模型RVE尺寸L及网格密度的方法,最后利用不同炭黑含量的RVE模型,对炭黑填充橡胶单轴拉伸力学行为进行了模拟.结果表明,炭黑填充橡胶RVE尺寸和粒径比(L/R)大于6时,计算结果几乎不受RVE尺寸影响;确定合适的RVE网格密度既能保证精度要求还能有效提高计算效率;对比有限元结果和实验结果,说明利用本文方法建立的代表体积单元能反映真实材料细观结构特点,能对橡胶宏观力学行为进行预测,对材料设计有一定的指导意义.

In this paper,the Random Sequential Absorption method(RSA)was employed to construct representative volume element of the CB-filled rubber,particles in the models were randomly dispersed and the radius of the particles obeyed the Gaussian distribution with an average value of 32nm.Take models contained 17.1%particles as example,methods to decide the dimension L and element density of the calculation models were discussed in detail.And then,the influence of CB content on the simple tensile behavior of the CB-filled rubber was modeled.The results indicate that,the calculation results were steady when the represent volume element have dimension of L larger than 6.Choose a suitable element density is necessary to improve the finite calculation efficiency.Compared the calculation results with the experimental data,it is clearly see that,the model constructed in this paper can reflect the true structure of the CB-filled rubber,and predict its macro mechanical behavior accurately.