Electrical degradation diagnosis of aerospace carbon fibre composites

航空航天碳纤维复合材料电退化诊断

• 批准号: 2886016
• 金额: --
• 依托单位: University of Strathclyde
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2886016
• 关键词: Electrical; degradation; diagnosis; aerospace; carbon

Reducing the use of metallic structures on aircraft, by replacement with lighter weight carbon fibre reinforced polymer (CFRP), enables optimisation of aircraft weight. Optimisation of weight for aircraft is critical and this includes the optimisation of the electrically powered propulsion system, where the biggest challenge is electrical power system weight. An example of a near-term aircraft with electrical propulsion is an electrical vertical take-off and land (eVTOL) aircraft, e.g. CityAirbus.CFRP has excellent mechanical properties, but it has poor conductivity compared to aluminium (~1000 times less). A gap in knowledge on the thresholds for failure of CFRP due to electrical current conduction, and methods to detect these in a non-destructive manner, results in industry standards requiring that CFRP and electrical equipment and cables are kept physically separate. This ensures that in the event of an electrical fault (e.g., due to insulation failure), electrical fault current will not flow through CFRP structures. This leads to volume and weight penalties: additional 30% weight on wiring infrastructure; 10% of power electronic weight, and 30 % of solid state circuit breaker weight is due to metallic casings; 25 % of motor weight is due to metallic end plates and casing. The use of CFRP for these functions in these components will bring weight reductions for the equipment of ~5 - 10 %.This project will investigate the correlation between the level of Joule heating sustained by a component and the reduction in mechanical properties due to thermal degradation. A major element of the project is the use of NDT methods to assess the level of degradation, and correlate to the level of Joule heating sustained. First, this develops a more efficient route to assessing degradation. This is critical, as there are a wide set of variable parameters which may influence the response of CFRP to Joule heating. Second, this provides a platform for future in-service assessment of CFRP components which have conducted electrical current.Key Objectives1. Review types of CFRP used, characteristics of electrical loading, and mechanical thresholds of CFRP in aircraft with electrical propulsion (e.g., EVTOL).2. Design test matrix for electrical loading of CFRP to lead to different levels of degradation.3. Experimental capture of datasets for degradation of CFRP due to electrical loading.4. Assessment of level of degradation using non-destructive test methods, verified by mechanical testing.5. From degradation thresholds observed, propose design and manufacture modifications to keep degradation below failure thresholds (e.g. layup, electrical bonding, manufacturing method).

通过使用重量更轻的碳纤维增强聚合物（CFRP）来减少飞机上金属结构的使用，可以优化飞机重量。飞机重量的优化至关重要，这包括电动推进系统的优化，其中最大的挑战是电力系统重量。具有电力推进的近期飞行器的示例是电力垂直起降（eVTOL）飞行器，例如CityAirbus JRP具有优异的机械性能，但与铝相比其具有差的导电性（低约1000倍）。由于电流传导导致CFRP失效的阈值以及以非破坏性方式检测这些失效的方法方面的知识差距，导致行业标准要求CFRP与电气设备和电缆保持物理分离。这确保了在电气故障的情况下（例如，由于绝缘失效），电气故障电流将不会流过CFRP结构。这导致体积和重量损失：布线基础设施上额外的30%重量; 10%的电力电子重量和30%的固态断路器重量归因于金属外壳; 25%的电机重量归因于金属端板和外壳。在这些部件中使用CFRP实现这些功能将使设备的重量减轻约5 - 10%。本项目将研究部件承受的焦耳加热水平与热降解导致的机械性能降低之间的相关性。该项目的一个主要内容是使用无损检测方法来评估退化水平，并与焦耳加热持续水平相关联。首先，这为评估退化提供了一种更有效的途径。这是至关重要的，因为有一个广泛的可变参数，可能会影响碳纤维增强塑料焦耳加热的响应。其次，这为将来对已传导电流的CFRP部件进行使用评估提供了一个平台。审查所用CFRP的类型、电负载的特性和CFRP在电推进飞机中的机械阈值（例如，EVTOL）。设计测试矩阵的碳纤维复合材料的电负载，导致不同程度的退化。实验捕获的数据集的退化CFRP由于电力负荷.使用非破坏性测试方法评估降解水平，并通过机械测试进行验证。根据观察到的退化阈值，提出设计和制造修改，以使退化保持在失效阈值以下（例如，铺层、电气接合、制造方法）。