A model for longitudinal tensile strength prediction of low braiding angle three-dimensional and four-directional composites

作者：Yuan Hui^*; Wen Weidong; Wang Yi; Zheng Zhenshan; Wu Xiong

来源：Science and Engineering of Composite Materials, 2017, 24(3): 447-453.

DOI：10.1515/secm-2014-0200

• braided composites
• damage analysis
• size effect
• strength

Based on random crack core theory, a model for predicting the longitudinal tensile strength of three-dimensional (3D) four-directional composites with low braiding angle is established. The model carries out accurate theoretical predictions of the longitudinal tensile strength of 3D four-directional braided carbon fiber/resin composites. The average stiffness method is used to calculate elastic constants of an inner single cell of 3D four-directional braided composites. Meanwhile, the corresponding relationship between failure probability of a unidirectional composite fiber bundle and stress level is given based on the random crack core model of the longitudinal tensile strength of a unidirectional composite. Furthermore, strength algorithms of low braiding angle 3D four-directional composites under different damage modes are built on the basis of the Tsai-Hill criterion. In this paper, the dispersion of single fiber strength is also considered in the model, so the size effect of the composite strength can be reflected effectively. At last, the longitudinal tensile strength of 3D four-directional braided carbon fiber/resin composites is predicted and analyzed, and the result shows that this model has high prediction accuracy.

• 出版日期2017-5
• 单位中国人民解放军海军装备研究院; 南京航空航天大学