二维编织陶瓷基复合材料应力-应变行为

STRESS-STRAIN BEHAVIOR IN 2D WEAVE CERAMIC MATRIX COMPOSITE

对二维编织陶瓷基复合材料拉伸应力-应变行为进行了试验研究和理论模拟.将二维编织结构简化为:正交铺层结构和纤维束波动结构.基于基体随机开裂、纤维随机断裂分布理论,得到正交铺层结构的应力-应变关系;基于体积平均方法,将纤维束波动部分进行分割,引入强度分析模型,得到纤维束波动部分的应力-应变关系.结合正交铺层部分和纤维束波动部分的应力-应变关系,得到二维编织结构的应力-应变行为,理论与试验吻合较好.

The stress-strain behavior of 2D weave ceramic matrix composite is studied by experimental and theoretical methods. The 2D weave structure is simplified as a crossply structure and a fiber bundle undulation structure. Based on the matrix strength stochastic distribution theory and the fiber failure stochastic distribution theory, the stress-strain behavior and the tangent tensile modulus are obtained for unidirectional composite （0° ply）. With the relationship between crossply and unidirectional ceramic matrix composite with the same material, the stress-strain behavior of crossply ceramic matrix composite can be obtained. A two-dimensional analytical method is proposed for fiber bundle undulation structure, with the composite strength model, the undulation structure is divided into sub-elements. The failure analysis is carried out considering the failure of different sub-elements in the fiber bundle undulation structure. Moreover, the stress-strain behavior of the undulation structure is obtained. Combining the crossply and the undulation structure＇s stress-strain behavior, the stress-strain behavior of of the 2D weave ceramic matrix composite is obtained; and the result agrees well with the experimental result.