提出了一个细观力学模型,用于预测非线性黏弹聚合物基复合材料的有效性质。该方法利用广义割线模量方法对单积分型热力学本构进行线性化,并运用Laplace变换技术将黏性问题转化为弹性问题。利用热力学本构拟合高密度聚乙烯的实验数据,得到基体的材料参数。利用该模型计算了玻璃微珠填充高密度聚乙烯复合材料(GB/HDPE)在恒应变率下的应力应变关系,计算结果与文献实验结果吻合较好。数值计算结果表明GB/HDPE复合材料表现出明显的非线性力学行为。该细观力学模型可以很好地预测复合材料非线性黏弹性性质。
A micromechanical model was proposed to estimate the overall nonlinear viscoelastic behavior for the particulate polymer composites. The method was based on the generalized secant method and Laplace transform technique. Schapery's thermodynamics constitutive law was used to simulate the experimental data of high-density polythene (HDPE) matrix and the material functions were identified. The stress and strain relation at a constant strain rate for HDPE-matrix composite filled with glass beads was analyzed. The predicted results agree well with the experimental ones. The results show that the GB/HDPE composites present obvious nonlinear behavior. The model can well predict the nonlinear viscoelastic properties for polymer composites.