考虑纤维束间粘接层的三维四向编织复合材料弹性性能数值预测

Numerical prediction for the elastic properties of 3D 4-directional braided composites considering adhesive layers

考虑了相邻纤维束之间的界面粘接效应,建立了考虑纤维束间粘接层的三维四向编织复合材料单胞有限元模型,较为真实地模拟了该材料的细观结构,讨论了相应的边界条件和约束条件,并采用有限元方法计算了该材料的等效弹性性能参数,计算结果与实验值符合较好。研究了等效弹性性能参数随不同编织角及体积分数的变化关系,得到了体胞的细观应力场,为强度分析提供数据。

Considering the effect of adhesive layers between adjacent yarns, a new FEM model of representative unit cell was established, which more really simulates the inner meso-structures of the 3D 4- directional braided composites. The boundary conditions and constrain conditions of the unit cell model were discussed and the effective elastic properties parameters were obtained by FEM calculation. The calculation results by the model agree well with the experimental results. The relations of the effective elastic properties varied with different braiding angles and fiber volume fractions are concluded by analyzing the results. The distribution of the stress in the composites was determined, which provide data for the strength calculations of the composites.