基于耦合法的二维三轴编织复合材料热学性能预测及验证

Thermal performance prediction and verification of 2D triaxial braided composites based on coupling method

为了改善传统方法建模划分网格繁杂和计算效率低的缺点,利用耦合建模法创建二维三轴编织复合材料的单胞模型,用耦合的思维将增强相单元网格与整体区域单元网格进行耦合处理,协调两者之间的位移场自由度和温度场自由度,通过匹配材料的热学性能,施加温度周期性边界条件,获得单胞模型的等效传热系数和等效热膨胀系数,基于该方法预测并分析编织角和纤维体积含量对各个方向的热传导系数和热膨胀系数的影响程度和规律。

In order to improve the shortcomings of the finite element unit-cell establish method based on traditional FEM, which has difficulty in meshing and calculation, a superimposed method was proposed. Based on the superimposed method, the finite element unit-cell model of two-dimensional triaxial braided composites was established. Based on the coupling method, the coordination relationship between degree of freedom of element grid of displacement field and temperature field from reinforcement and matrix were given, and the match method of superimposed region thermal properties and the periodic boundary conditions of the unit-cell model temperature field were determined. The equivalent thermal conductivity coefficient and the equivalent thermal expansion coefficient of the unit-cell model were obtained by applying the periodic boundary conditions. Based on this method, the thermal properties of two-dimensional triaxial braided composites were predicted and analysed. The results show that different braiding angles and fiber volume faction have certain effects on the thermal conductivity coefficient and thermal expansion coefficient in different directions.