High-temperature oxidation damage in C/SiC composite, alongside mechanical failure, has becoming a focal point of developing high performance motor components. However, most of existing models focus on only one field and thus can hardly to simulate a complete process. To address this, a thermodynamically consistent phase field model tailored specifically for C/SiC composites is proposed. This model offers a long-desired capability to encompass both carbon fiber oxidation in oxidation controlled stage and mechanical fracture, as well as their intricate interactions. Instead of relying on predefined fields or empirical knowledge, our model determines the oxygen field distribution and the evolution of new cracks through the differential equations rigorously, thereby providing a more accurate estimation of the location and extent of the failure process. The validity and reliability of our model have been tested through a few numerical studies. The proposed model has successfully captured the intricate characteristics of micro-crack propagation in C/SiC composites, including the saturation of cracks originating from the SiC matrix and the fracture process of carbon fibers after oxidation. As a result, our research is anticipated to be serving as an invaluable foundation for quantitative investigations into the performance of C/SiC composites, paving the way for the development of more robust and reliable high-temperature C/SiC composites.

中文翻译：

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使用相场模型对 C/SiC 复合材料的高温渐进失效进行建模：氧化速率控制过程


C/SiC 复合材料中的高温氧化损伤以及机械故障已成为开发高性能电机部件的重点。然而，现有的模型大多只关注一个领域，因此很难模拟一个完整的过程。为了解决这个问题，提出了一种专门为 C/SiC 复合材料定制的热力学一致相场模型。该模型提供了一种渴望已久的功能，可以涵盖氧化控制阶段的碳纤维氧化和机械断裂，以及它们错综复杂的相互作用。我们的模型不依赖于预定义的场或经验知识，而是通过微分方程严格地确定氧场分布和新裂纹的演变，从而更准确地估计失效过程的位置和程度。我们模型的有效性和可靠性已经通过一些数值研究进行了测试。所提出的模型成功地捕捉了 C/SiC 复合材料中微裂纹扩展的复杂特征，包括 SiC 基体裂纹的饱和和碳纤维氧化后的断裂过程。因此，我们的研究有望成为定量研究 C/SiC 复合材料性能的宝贵基础，为开发更坚固、更可靠的高温 C/SiC 复合材料铺平道路。