钛基复合材料中的微区应力分布

Microstress distribution of titanium matrix composites

使用三纤维/基体有限元模型研究了纤维失效和基体屈服后钛基复合材料内微区应力分布,结果表明:钛基复合材料内纤维失效端面的轴向应力降为0,承载能力降低,相邻基体和未失效纤维的承载能力升高;随着纤维体积分数的增大,失效后应力和失效前应力的比值增大;当中心纤维断裂时,纤维体积分数高的复合材料立即失效,且失效形式为共面失效;对于纤维体积分数低的复合材料,基体屈服对纤维与基体之间的载荷传递有重要的影响.

The three fiber/matrix finite element model was developed to study the microstress distribution of titanium matrix composites under the condition of the fiber failure and the matrix yield. The results showed that the axial stress at the position of fiber failure drops to zero, the load-carrying capacity of failure fiber decreases, while the load-carrying capacity of the neighboring matrix and fiber increases. The ratio of stress after and before fiber failure increases with increasing fiber volume fraction. When the middle fiber breaks, the failure occurs immediately in composites at high fiber volume fraction, and the failure location in neighboring fiber occurs in the identical fracture plane. For composites at low fiber volume fraction, the matrix plasticity significantly influences on the load transfer between the fiber and the matrix.