Ceramic Matrix Composites Condition Assessment and Damage Monitoring

陶瓷基复合材料（CMC）长期以来一直被认为是燃气涡轮机发动机中的高温应用，现在一些先进的设计包括这些。在未来的民用发动机设计中实施CMC具有强大的商业驱动力，主要作为提高发动机工作温度、提高燃料效率和减少温室气体排放的手段。该项目的目标是探索适用于CMC的状态评估和损坏监测的技术。这些方法可能包括微波介电谱、动态模量损耗角正切（与中断疲劳结合）、过程补偿谐振测试和太赫兹成像等方法。在每种情况下，评估测试试样的状况，以便在一次车间访问时对零件进行判决，以便传递到第二个服务间隔。使用X射线计算机断层扫描（CT）来了解损坏如何在CMC中传播，可以提高对状况评估技术的理解，并有助于了解材料表面状况的影响。此外，对具有设计相关架构的CMC的损伤传播特性差异的调查将补充罗尔斯·罗伊斯公司正在进行的CMC研究开发计划。

Ceramic matrix composites (CMCs) have long been considered for high temperature application within the gas turbine engine, and some advanced designs now incorporate these. There is a strong commercial drive to implement CMCs into future civil engine designs, mainly as a means to increase engine operation temperatures, improve fuel efficiency and reduce greenhouse gas emissions. The objective of the project is to explore techniques applicable for condition assessment and damage monitoring of CMCs. These potentially include methods such as microwave dielectric spectroscopy, dynamic modulus loss tangent (in conjunction with interrupted fatigue), process compensated resonance testing and terahertz imaging. In each case assessing the condition of test coupons with a view to sentencing parts at one shop visit for pass-on to a second service interval.The use of X-ray Computed Tomography (CT) to understand how damage propagates in CMCs may improve understanding and help to inform the condition assessment techniques as well as understand the influence of material surface condition. Additionally, investigations into the difference in damage propagation characteristics of CMCs with design relevant architectures will complement the ongoing CMC research development programmes within Rolls-Royce plc.