三维四向编织复合材料的单胞应力场分布

摘要

基于三维四向编织复合材料预制件的细观结构,提出了螺旋型纤维等效模型.采用多相有限元数值法获得了三维四向编织复合材料的轴向拉伸应力应变关系,通过有限元计算得到了材料单胞模型的细观应力分布.结果表明,螺旋型纤维等效模型的数值预报结果与实验数据基本吻合,证明了该单胞模型符合三维四向编织复合材料的实际细观结构,该模型能有效地计算三维编织复合材料单胞细观应力分布场,为后续的强度研究与破坏分析奠定了基础.%Based on the meso-structure of prefabricated member of 3 D four-directional braided composites, the helix geometry model was presented. According to the unit cell model, the longitudinal tensile stress-strain relationships are obtained through a finite multiphase element numerical method(FMEM). The stress fields in a unit cell are obtained. The numerical calculations of the helix geometry model agree well with the experiment data. The calculated results demonstrate that the unit cell model fits in with the practical microscopic structure of 3D four-directional braided composites. The present model can compute the unit cell stress field of 3 D braided composites effectively and lays a foundation for the follow-up strength research and failure analysis.