Aircraft Electrical Isolation Laminate for Lightning Arcing Control

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Solution Overview

Problem

Composite materials used in aircraft structures often have low electrical conductivity, posing challenges for safe electrical current dissipation during lightning strikes, which can lead to voltage differentials and arcing, particularly near fuel tanks.

Innovation Solution

Manufacturing an electrical isolation component using a core of reinforcing fibers embedded in a thermoplastic matrix with an outer layer of glass fibers, which is designed to resist electrical conduction and arcing by distributing electrical current safely.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If composite materials are used in aircraft structures, then weight is reduced and strength is improved, but electrical conductivity is insufficient for safe current dissipation during lightning strikes

Engineering Contradiction:
Improveaircraft weightVSAvoidelectrical current dissipation capability
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent applies composite materials by combining carbon fiber reinforcement with thermoplastic matrix material to create a component that exhibits both mechanical strength and electrical conductivity. The carbon fibers provide the necessary conductive pathways for lightning current dissipation while the thermoplastic matrix binds the fibers together to form a structurally sound component that also contributes to weight reduction.

Inventive Principle:
Principle #40Composite materials

2Reliability

If copper foil and copper paint layers are applied on aircraft skin, then electrical conductivity is improved for lightning protection, but manufacturing complexity and number of layers increase

Engineering Contradiction:
Improveelectrical current dissipation capabilityVSAvoidnumber of coating layers
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the structural reinforcement function and electrical conductivity function into a single integrated component. Instead of applying separate copper foil and copper paint layers over the composite skin, the carbon fiber reinforced thermoplastic component itself provides both structural support and electrical conductivity, eliminating multiple coating layers and simplifying the overall structure.

Inventive Principle:
Principle #5Merging (Combining)

3Use of energy by moving object

If voltage differentials are allowed to exist during lightning strikes, then electrical energy distribution occurs, but arcing and ignition hazards increase near fuel tanks

Engineering Contradiction:
Improveelectrical energy distributionVSAvoidarcing and ignition hazard
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent changes the electrical parameter of the aircraft structure by incorporating conductive carbon fiber reinforced thermoplastic components. This modification alters the electrical conductivity parameter of the composite materials, enabling controlled current flow and reducing voltage differentials that would otherwise lead to dangerous arcing and ignition hazards near fuel tanks during lightning strikes.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively prevents electrical arcing and ensures safe distribution of electrical current during lightning strikes, reducing the risk of ignition hazards in aircraft structures.

Implementation Method 1

applying pressure to the outer ply and core preform, thereby causing consolidation of the reinforcing fibers and matrix material

Methodology Applied
Scientific EffectThermoplastic consolidation:

Implementation Method 2

an electrically-insulating outer ply overlaying the core, said outer ply comprising glass fibers

Methodology Applied
Scientific EffectElectrical insulation: Electrical Resistance

Implementation Method 3

said reinforcing fibers comprise carbon fibers

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP4223489B1Aircraft electrical isolation component and method of manufacturing electrical isolation component
Publication Date: 2025.07.16 SHORT BROTHERS PLC
  • EP4223489B1 patent drawingFigure 1A~1C
  • EP4223489B1 patent drawingFigure 2A~2B
  • EP4223489B1 patent drawingFigure 3

AI summary

Disclosed is a method of manufacturing an electrical isolation component which comprises overlaying an electrically-insulating outer ply comprising glass fibers on a core preform comprising reinforcing fibers and a thermoplastic matrix material and applying pressure to said outer ply and core preform, thereby causing consolidation of said reinforcing fibers and matrix material. Pressure is removed and said thermoplastic material hardens, thereby forming a laminate structure from the outer ply and the consolidated reinforcing fibers and matrix material. The reinforcing fibers and said glass fibers are formed of different materials. Also disclosed is an electrical isolation component having a core formed of reinforcing fibers embedded in a thermoplastic matrix material; and an electrically-insulating outer ply overlaying said core.