Fracture and Crack Tip Behavior in Fiber-Reinforced Ceramic-Matrix Composites

小行星9307877 该项目利用PI在制备具有独特微观结构和可控界面性能的陶瓷基复合材料（CMC）方面的经验，采用新的加工技术。 裂纹扩展研究将在配备机械加载台的扫描电子显微镜（SEM）中进行。 断裂实验将在3点弯曲模式下进行。 光纤桥接应力将通过激光拉曼光谱（LRS）测量。 裂纹扩展的机制和局部应力-位移关系的原位测量将被纳入一个分析模型的基础上的凝聚裂纹的方法。 本研究的目的是为纤维增强陶瓷基复合材料（FRCMC）的断裂和裂纹扩展机制提供一个全面的，但基本的理解。 %%% 该项目旨在了解纤维增强陶瓷基复合材料（FRCMC）断裂和裂纹扩展的基本机制。 它从独特制备的CMC开始，具有可控的界面特性和微观结构。 配备有机械加载台的扫描电子显微镜（SEM）允许原位研究其裂纹扩展行为。 三点弯曲模式的测试为实际应用提供了信息。 最后，利用激光拉曼光谱测量了光纤的桥接应力。 这个综合性的项目为特定应用的材料设计提供了有用的信息。 ***

9307877 Singh This proposed project utilizes the PI's prior experiences in preparing ceramic matrix composites (CMC) of unique microstructures and controlled interfacial properties with novel processing techniques. Crack growth studies will be performed within a Scanning Electron Microscope (SEM) equipped with a mechanical loading stage. Fracture experiments will be done in a 3-point flexure mode. Fiber bridging stress will be measured by Laser Raman Spectroscopy (LRS). The mechanism of crack growth and in situ measurements of the local stress-displacement relations will be incorporated into an analytical model based on the cohesive crack approach. The objective of this study is to provide a comprehensive but fundamental understanding of the mechanisms of fracture and crack propagation in fiber reinforced ceramic matrix composites (FRCMC). %%% This proposed project seeks to understand the fundamental mechanisms of fracture and crack propagation in fiber reinforced ceramic matrix composites (FRCMC). It starts with uniquely prepared CMC with controlled interfacial properties and microstructures. A Scanning Electron Microscope (SEM) equipped with a mechanical loading stage allows the study of its crack growth behaviors in situ. Testing with a 3-point flexure mode provides information to practical applications. finally, the fiber bridging stress will be measured with the use of Laser Raman spectroscopy. This comprehensive project offers the useful information in the design of materials for specific applications. ***