中文摘要：

基于纤维增强连续介质力学理论，提出一种超弹性本构模型来描述机织复合材料织物在成形过程中由于大变形所引起的非线性各向异性力学行为。在这一模型中，应变能函数被分解成两部分：一部分代表由于经纱和纬纱各自拉伸所产生的拉伸应变能；另一部分代表由于经纱和纬纱之间角度变化而产生的剪切应变能。本构模型中所需的材料参数通过对机织复合材料织物的单向拉伸以及偏拉试验数据的分析与拟合来求得。利用对一平纹机织复合材料的单曲率半球形冲压成形试验进行有限元模拟来验证模型。模拟结果与试验结果对比表明所提出的超弹性本构模型能够很好地表征机织复合材料在大变形下的非线性各向异性力学行为。这一本构模型具有简单实用、材料参数容易确定的优点。该模型对于机织复合材料成形的数值模拟与成形工艺优化设计有着重要的意义。

英文摘要：

Based on fiber reinforced continuum mechanics theory, a simple hyperelastic constitutive model is developed to characterize the anisotropic nonlinear material behavior of woven composite fabrics under large deformation during forming. The strain energy functions for the hyperelastic model is decomposed into two parts representing the tensile energy from weft and warp yam fiber stretches and sheafing energy from fiber-fiber interaction between weft and warp yams, respectively. The equivalent material parameters in the hyperelastic constitutive model can be obtained by matching experimental load-displacement data of uni-axial tensile and bias-extension tests on woven composite fabric. The model is validated by implementing numerical simulations on a hemispherical stamping of a square balanced plain weave composite fabric at room temperature. Comparisons between simulation results and experimental data show that the proposed hyperelastic model can effectively characterize the anisotropic material behavior of woven composites under large deformation. The proposed model is simple and easy for material parameter determination. The development of this anisotropic fiber reinforced hyperelastic model is critical to the numerical simulation and processing optimization of woven composites forming.