摘要
基于单胞分析模型,采用改进的刚度平均化方法,对三维四向和五向编织复合材料的各单胞及各层的弹性性能进行预测与分析;进一步,利用材料力学理论,推导材料的弯曲模量,分析编织角、纤维体积含量以及试件尺寸对其的影响,并与拉伸模量及试验值进行比较。结果表明,三维编织复合材料的不同胞体及各层之间的弹性性能存在较大差异,并且材料的弯曲模量大于拉伸模量。研究还表明,编织角和纤维体积含量是影响材料弯曲模量的重要参数,弯曲弹性性能受试件厚度的影响比宽度大,当宽度和厚度达到一定尺寸时,弯曲模量会趋于定值。此外,三维五向编织复合材料的弯曲弹性性能明显优于三维四向编织复合材料。
Based on the unit model, the elastic properties of three-dimensional and four-directional（3D ＆ 4D） braided composites and three-dimensional and five-directional（3D ＆ 5D） braided composites have been predicted by the improved average stiffness. Furthennore, material mechanics has been used to deduce the bending elastic modulus of the composites. The influence of the braiding angle and the fiber volume fraction as well as the size of the samples on the bending elastic modulus has been analyzed and the predicted results have been compared with the tension modulus and the experimental values. The results indicated that the elastic properties of the different cells and the layers of composites have shown significant difference and the bending modulus is bigger than the tensile modulus. The braiding angle and the fiber volume fraction are important parameters of the bending properties of three-dimensional braided composites. The thickness of specimen has more significant effect on the bending performance than the width, but when the sample comes to a certain size, the bending modulus become invariable. In addition, the bending properties of 5D braided composites are better than that of 4D braided composites.
出处
《机械强度》
EI
CAS
CSCD
北大核心
2008年第4期623-627,共5页
Journal of Mechanical Strength
基金
航空科学基金(04B51045)
北京市教育委员会共建项目建设计划(XK100060522)
北航博士创新基金资助~~
