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基于三维四向和五向编织复合材料的细观结构和单胞模型,对三维四步法矩形截面编织复合材料悬臂梁的振动阻尼性能进行了理论分析,研究了编织角、纤维体积分数等工艺参数对材料振动阻尼特性的影响,并与实验结果进行了对比。对三细胞模型进行了改进,采用混合律得到了材料的总体刚度,进而得到一阶固有频率。此外,还分别计算了一个周期内不同走向纱线和基体振动消耗的能量,以及总振动能量,得到了材料的损耗因子。结果表明,对于三维四向和五向编织复合材料,一阶固有频率随编织角的增加而减小,随纤维体积分数的增加而增大;而损耗因子随编织角的增加而增大,随纤维体积分数的增加而减小,并表现出明显的非线性变化规律。
Based on the mesostructure and unit cell model of three-dimensional four-directional and five-directional braided composites, the vibration damping capacity of three-dimensional four-step rectangular cross-section braided composite cantilever beam was theoretically analyzed. The braided angle and fiber volume fraction The influence of the parameters on the vibration damping properties of the materials is compared with the experimental results. The three-cell model is improved, and the overall stiffness of the material is obtained by a mixing law, and the first-order natural frequency is obtained. In addition, the energy consumption of different directions of yarn and matrix vibration in one cycle and the total vibrational energy were also calculated, and the loss factor of the material was obtained. The results show that for three-dimensional four-directional and five-directional braided composites, the first-order natural frequency decreases with the increase of braid angle and increases with the increase of fiber volume fraction, while the loss factor increases with the increase of braid angle Fiber volume fraction increases and decreases, and showed a significant non-linear variation.