树脂基三维编织复合材料粘弹性能的数值预报

Numerical Prediction of Viscoelastic Behaviors of Three-dimensionally Braided Resin Matrix Composites

建立了基于三细胞模型数值预报三维编织复合材料粘弹性能的方法。首先构造了三维编织复合材料的三细胞模型并施加周期性边界条件,随后利用标准线性固体模型模拟树脂基体的粘弹性能,导出基体的松弛模量,再通过有限元计算及Prony级数拟合,得到三种胞元的粘弹性参数。然后根据三种胞元的体积分数和粘弹性参数,利用三个标准线性固体模型并联,模拟得到三维编织复合材料沿编织方向的粘弹性参数和蠕变本构关系。最后,分析了编织角和纤维体积含量对粘弹性能的影响。

A numerical method for predicting viscoelastic properties of 3D braided composites based on the three-cell model was presented.First,the three-cell model of 3D braided composites was constructed and periodic boundary conditions were applied.Relaxation modulus of the matrix was derived by using a standard linear solid model to simulate the viscoelastic properties of the resin matrix.Then viscoelastic parameters of unit cells were obtained through the finite element method and the Prony series fitting.Viscoelastic parameters and creep constitutive relations along the braiding direction of 3D braided composites were obtained by parallel connecting with three standard linear solid models based on the volume fraction and viscoelastic parameters of the unit cells.Finally,the influence of the braiding angle and the fiber volume fraction on the viscoelastic properties along the braiding direction was analyzed.