橡胶-帘线增强复合材料的本构模型及数值模拟

Constitutive Modeling and Numerical Simulation of Rubber-Cord Composites

针对有两族帘线的橡胶—帘线增强复合材料,基于Spencer的连续介质力学不变量理论,提出了一种非线性超弹性本构模型。通过引入两个帘线排列方向的结构张量把单位体积的自由应变能分解为便于参数识别的体积变形、等容变形和各向异性变形三部分。分别用纯橡胶单轴拉伸实验,沿帘线方向单轴拉伸实验数据拟合得到等容变形和各向异性变形的材料参数。通过COMSOL弱形式偏微分方程,对橡胶-帘线增强复合材料在有限变形下的单轴拉伸进行数值模拟。预测了帘线在不同排列方向条件下的力学性能,为轮胎的力学分析打下了坚实的基础。

Based on the invariant theory of continuous medium mechanics by Spencer,a nonlinear hyperelastic constitutive model is developed for rubber-cord reinforced composite material.The strain energy function is additively decomposed into three parts nominally representing volumetric,isochoric and anisotropic parts with structure tensors for the two families of cords.Material parameters for the isochoric and anisotropic parts are obtained by matching uniaxial tensile testing data of pure rubber and along cord direction,respectively.A weak-form PDE designed for COSMOL is applied for the simulation of uniaxial tension of the rubber-cord composites under finite strain.The mechanical properties of the rubber-cord composites under various fiber orientations are then predicted.The model lays a solid foundation for the mechanics analysis of tire.