考虑双拉耦合的复合材料编织物非正交本构模型

A Nonorthogonal Constitutive Model for Woven Composites Involving Biaxial Tension Coupling

基于连续介质力学理论,将复合材料编织物的双轴拉伸效应引入到前期提出的非正交本构模型中,提出了一种考虑双拉耦合的复合材料编织物非正交本构模型.给出了模型参数的确定方法,并通过拟合单轴拉伸、不等比双轴拉伸和偏轴拉伸实验数据,得到了本构模型参数.利用该模型对双轴拉伸和双球冲压实验进行了有限元模拟,并将模拟结果和实验结果进行对比,验证了所提出本构模型的可靠性,该模型能更好地表征复合材料编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.这一本构模型具有结果精确、参数容易确定的优点,为编织复合材料成形的数值模拟和成形工艺优化奠定了理论基础.

Based on the continuum mechanics theory,a nonorthogonal constitutive model for woven composites involving biaxial tension coupling was developed.The biaxial tension coupling effects of the composite fabric were introduced into a previously built nonorthogonal constitutive model,and the method to identify the material parameters in the constitutive model was provided.In the fitting of experimental data from the uniaxial tensile test,the biaxial tensile test at different stretch ratios and the bias extension test,the model parameters were obtained.The present model was validated through comparison between the numerical results and the experimental data out of a biaxial tensile test and a double-dome stamping test,which indicated that the model was reliable to characterize the highly nonlinear and strongly anisotropic mechanical behaviors of the composite fabric in large deformation.The new model has the merits of accurate results and easy determination of material parameters,making a theoretical foundation for the numerical simulation and optimization of the woven composite forming process in the future.