An electrical metrology roadmap for carbon fibre composites to enable integrated systems design

The pathway to decarbonisation of aviation is complex, requiring a combination of new technologies, fuels and operations. Electrification of power and propulsion systems is an underpinning technology for this net-zero transition, but achieving high power density targets whilst maintaining the resilience required for safety critical applications remains significantly challenging. Exploitation of carbon fibre reinforced polymer (CFRP) structures for equipment casings, and close physical integration of electrical power systems with CFRP, provides an opportunity to increase power density and hence, efficiency of future aircraft. The design of integrated electrical-CFRP structure systems is hindered by the lack of accurate knowledge of the electrical properties of the CFRP when the composite structure couples with the electrical power system functionality. Capturing these electrical properties to realistically represent the scenarios where coupling occurs, necessitates reliable composite testing methodologies supported by appropriate measurement techniques and best metrological practices. This paper will review and assess the established approaches from the literature used to prepare, test, measure, and characterise the electrical properties of sample composite materials. It will experimentally demonstrate the limitations of these established methods for capturing realistic and representative datasets to reliably inform subsequent design requirements and modelling approaches for advanced fault analysis studies.