To predict the nonlinear stress‐strain behavior and the rupture strength of orthotropic ceramic matrix composites (CMCs) under macroscopic plane stress, a concise damage‐based mechanical theory including a new constitutive model and two kinds of failure criteria was developed in the framework of continuum damage mechanics (CDM). The damage constitutive model was established using strain partitioning and damage decoupling methods. Meanwhile, the failure criteria were formulated in terms of damage energy release rate (DERR) in order to correlate the failure property of CMCs with damage driving forces, and the maximum DERR criterion and the interactive DERR criterion were suggested simultaneously. For the sake of model evaluation, the theory was applied to a typical CMC with damageable and nonlinear behavior, that is, 2D‐C/SiC. The damage evolution law, strain response and rupture strength under incremental cyclic tension along both on‐axis and off‐axis directions were completely investigated. Comparison between theoretical predictions and experimental data illustrates that the newly developed mechanical theory is potential to give reasonable and accurate results of both stress‐strain response and failure property for orthotropic CMCs.

中文翻译：

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宏观平面应力作用下正交各向异性陶瓷基复合材料的本构模型和破坏准则

为了预测宏观平面应力下正交各向异性陶瓷基复合材料（CMC）的非线性应力应变行为和断裂强度，在连续介质框架下建立了一个简明的基于损伤的力学理论，包括新的本构模型和两种破坏准则损伤力学（CDM）。使用应变分配和损伤解耦方法建立损伤本构模型。同时，根据损伤能量释放率（DERR）制定了失效准则，以使CMC的失效特性与损伤驱动力相关联，同时提出了最大DERR准则和交互式DERR准则。为了进行模型评估，将该理论应用于具有损坏和非线性行为的典型CMC，即2D-C / SiC。全面研究了沿轴向和离轴方向的增量循环拉伸作用下的损伤演化规律，应变响应和断裂强度。理论预测和实验数据之间的比较表明，新开发的力学理论有可能为正交各向异性CMC提供合理，准确的应力-应变响应和破坏特性结果。