考虑双拉耦合的复合材料编织物各向异性超弹性本构模型

Anisotropic hyperelastic constitutive model with biaxial tension coupling for woven fabric composites

为了准确描述复合材料编织物的各向异性力学特性,首先,基于纤维增强复合材料连续介质力学理论提出了一种考虑纤维双拉耦合的复合材料编织物各向异性超弹性本构模型,该模型中单位体积的应变能被解耦为便于参数识别的纤维拉伸变形能、双拉耦合引起的挤压变形能和纤维间角度变化产生的剪切变形能;然后,给出了模型参数的确定方法,并通过拟合单轴拉伸、双轴拉伸和镜框剪切实验数据得到了本构模型参数;最后,利用该模型对双轴拉伸和镜框剪切实验进行了数值仿真,并将模拟结果与实验结果对比分析。结果表明:提出的本构模型适用于表征复合材料编织物在成型过程中由于大变形引起的非线性各向异性力学行为。所得结论表明提出的本构模型具有简单、实用的优点,且材料参数容易确定,可为复合材料编织物成型的数值模拟和工艺优化奠定理论基础。

In order to characterize the anisotropic mechanical behaviors of woven fabric composites precisely,based on fiber reinforced composite continuum medium mechanics theory,an anisotropic hyperelastic constitutive model with biaxial tension coupling of fiber for woven fabric composites was proposed firstly.The unit-volume strain energy in the model was decomposed into the deformation energy of fiber elongation,the compaction deformation energy due to biaxial tension coupling and shear deformation energy due to the change of angels between fibers.Then,determination approach for model parameters was given,and parameters of constitutive model were obtained by fitting the uni-axial tensile,biaxial tensile and picture-frame shear experiment data.Finally,the numerical simulation of biaxial tensile and picture-frame shear experiments was conducted by the model,and the simulation results were contrasted and analyzed with experiment data.The results show that the constitutive model proposed is suitable to characterize the non-linear and anisotropic mechanical behaviors cased by large deformation of woven fabric composites during forming process.The conclusions obtained show that the proposed constitutive model has advantages of simple and useful,and the determination of material parameters is easy,which can lay down the theoretical foundation for the numerical simulation and processing optimization for the forming of woven fabric composites.