Several electrical functions provided by a metallic airframe are not directly provided anymore by a
CFRP (Carbon Fiber Reinforced Polymer) airframe. A set of metallic conductors called ESN (Electrical
Structural Network) or MBN (Metallic Bonding Network) were designed and integrated on the latest
composite aircraft to compensate for the a priori poor electrical performance of the CFRP.
Efforts on the electrical distribution technologies, and short circuit prevention technologies (‘’fast
tripping’’), makes it possible to reduce the overall current load that would be injected into the carbon
structure. Research programs have in their objective the optimization, or suppression, of the MBN
which industrial footprint on the product is substantial. However, an important hurdle is the
knowledge of the capability of a CFRP junction to accept a certain amount of current, either
permanently and accidentally (in electrical fault conditions).
The ‘’MBN free’’ / ‘’No-MBN’’ concepts makes necessary to understand the effect of an electrical flow
into those junctions over long period of time, or associated to short transient events to understand
the possible knockdown effects on the mechanical properties and possible microdefect accumulation. Ideally, beyond the results of an empirical approach, a physical
model of the physical phenomena at stake making possible to anticipate performances would be a
significant breakthrough.
The objectives of the research and PhD are as follows:
- to understand the CFRP interaction with an electrical flow,
- to provide the knockdown laws enabling the ‘’MBN free’’ electrical distribution concepts, eventually associated to some sizing models,
- to pave the way to a methodology for certifying those concepts without having to test all configurations of junctions.
You will find more details on the attached document.
