三维四向编织复合材料刚度的细观力学设计

 为了实现工程应用中三维编织复合材料的灵活设计,合理优化纤维束结构参数使得三维编织复合材料宏观刚度达到要求。基于非连续介质力学方法建立桁架结构单胞模型,采用有限元法预估复合材料的有效弹性模量,以材料质量最轻和刚度要求为目标,选用遗传算法优化细观结构参数。对纱线线密度和编织节距长度的优化结果验证,实验表明,桁架单胞模型结合遗传算法可以为满足弹性性能要求的三维编织复合材料快速地找到最优的细观结构参数。

Stiffness optimization of 3-D braided composites with micromechanical method

To realize the tailor ability of 3-D braided composites for applications,the microstructure parameters of 3-D braided composites are optimized to meet the need of macro stiffness property based on the micromechanics methodology.The truss model of unit cell is developed based on non-continuum mechanics,and finite element method is utilized to predict the effective elastic modulus of composites.With weight minimum and stiffness requirements as the objective,the genetic algorithm is used in the optimization of microstructure parameters of the composites.The comparisons between the computational and experimental results show that the combination of the truss model of unit cell and genetic algorithm can easily find out optimal microstructure parameters to satisfy the elastic requirements of 3-D braided composites.Here the microstructure parameters include the yarn linear density and the pitch length.