[4A1] A predictive model for electrical fault uncertainty in carbon fibre-reinforced polymer
M Osama, C Jones and B Stephen
University of Strathclyde, UK
Twin trends for the reduction of emissions from aircraft are light-weighting of structures and electrification of power systems. Due to the lower density and superior mechanical properties of carbon fibre-reinforced polymer (CFRP) compared to aluminium, more than 50% of aircraft structures are CFRP. The design of integrated electrical power and CFRP systems is challenged by limited knowledge of the failure modes of these integrated systems. This includes understanding degradation processes resulting in the conduction of electrical fault current through CFRP. This degradation includes chaffing of an electrical cable on a CFRP component, removing the electrically insulating epoxy surface layer from the CFRP and exposing electrically conducting carbon fibres. As abrasion progresses, the electrical resistance of CFRP reduces. Once resistance drops below a threshold, an electrical fault current can flow from the chaffed cable through a CFRP component and result in degradation from localised Joule heating. This research presents a systematic methodology to quantify the uncertainty of electrical properties due to multiple degrees of surface abrasion. Due to limited exemplar data, a Bayesian linear regression framework is employed to quantify the uncertainties in the relationship between surface abrasion and CFRP electrical properties. This framework allows for subsequent prediction of the plausible range of electrical resistance through multiple surface degradation stages, providing a pathway for resilient, integrated electrical power and CFRP systems design to optimise system weight and performance.
