A methodology for design and selection of multifunctional CFRP for lightweighting aerospace structures

Academic Institution: University of Strathclyde

Academic Supervisor: Dr Catherine Jones

Industry Partner: Rolls Royce

PhD Student: Muhammad Hijaaj Tahir

Desire to reduce fuel burn and emissions, drives twin trends for electrification of aircraft power systems and use of strong and light-weight, carbon-fiber reinforced polymer (CFRP) composite aircraft structures. Significant challenge is presented by the incompatibility of these trends, due to the low electrical and thermal conductivity of CFRP. Multifunctional CFRP (MF CFRP) offer a route to combine electrical and structural systems. Interdependencies between the electrical, thermal and structural properties of CFRP, combined with structural and electrical system requirements, present significant research challenge. This project aims to create a methodology for efficient design and selection of multifunctional composites, enabling improved performance of future aircraft.

Electrification of power and propulsion systems can support the aviation decarbonisation which currently contributes 3% of global greenhouse gas emissions. A significant challenge for these systems is the step change in power ratings (MW to Multi-MW) and the associated high-power densities required for electrical power system equipment.  For example, power density of electrical machines needs to rise from 3 kW/kg of 2020 to 20 kW/kg by 2035 [1].

CFRP offers significant opportunities to lightweight components. The design of MF CFRP based components with combined electrical, thermal and structural functionality offers a route to improve the power density of electrical power systems by replacing aluminium with CFRP, which is 30% less dense than aluminium. A challenge to the design of MF CFRP components is the need for a material design and selection methodology to integrate with electrical, thermal and structural system design.

The research has developed a methodology for designing and selecting CFRP for use in multifunctional aerostructure applications. It provides a systematic approach to capture design constraints for MF CFRP based on the interdependent mechanical, electrical, and thermal requirements of aircraft structural components and electrical power equipment. The methodology first assesses the mechanical, electrical and thermal requirements for a target MF CFRP component and systematically identifies and ranks possible solutions. If no solutions are identified, the methodology iteratively systematically adjusts one or more of CFRP design factors, wider aircraft EPS and structural system parameters to adjust component requirements to identify alternative pathways to reach a MF CFRP solution.

Key results/outcomes

  • A methodology for design and selection of MF CFRP which provides both structural functionality and carries electrical current for part of the electrical power system of the aircraft.

·       The methodology enables:

  • System design trades for MF CFRP to increase power density of electrical power systems on aircraft.

  • Prioritisation of knowledge of CFRP properties needed for MF CFRP design.

  • Identification limitations associated with the application of CFRP as a multifunctional material.

Conference/Journal papers

Conference paper: Tahir, M HijaajJones, C. E., Whitfield, R. I., Norman, P. and Burt, G., “A framework for efficient design of multifunctional-CFRP for future aircraft”, In Proceedings of the 20th European Conference on Composite Materials, ECCM20, 2022, pp. 461-468.

Journal Paper: Tahir, M HijaajJones, C. E.Whitfield, R. I., and Burt, G., “A methodology for design and selection of MF CFRP for aerostructures”, Composite Structures, (in progress, expected submission: 31st January 2025)

Contact details

Dr Catherine Jones

Chancellor's Fellow (lecturer), Institute for Energy and Environment, University of Strathclyde

Muhammad Hijaaj Tahir

PhD Student, University of Strathclyde