Double-Walled Channel Formers for Aircraft Fuselage Stiffness

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Solution Overview

Problem

The existing aircraft fuselage structures limit the window width due to the spacing requirements of lateral struts, which affects passenger comfort and the ability to fit air conditioning system components, as the spacing between formers is determined by strength requirements and stiffness needs.

Innovation Solution

A structural construction with channel-like main formers that are double-walled, allowing for increased spacing between formers, accommodating wider windows and air conditioning components, where at least one air line is disposed between the main former and the outer skin, and optionally using thermally insulating materials to minimize temperature and noise impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional single-walled formers are used, then the structure is simpler and easier to manufacture, but the spacing between formers must be smaller to maintain sufficient stiffness

Engineering Contradiction:
Improveformer manufacturing simplicityVSAvoidspacing between formers
Core Design Contradiction:
Ease of manufactureVSLength of stationary object

Solution Approach 1:

The former cross-section is changed from a single-walled configuration to a double-walled channel-like structure. This dimensional change in the cross-sectional geometry provides additional stiffening capability, allowing the formers to be spaced further apart while maintaining the required lateral stiffness of the fuselage.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The double-walled channel-like former structure creates a composite structural system with two walls extending at a spacing from one another. This composite configuration provides enhanced stiffness-to-weight ratio compared to single-walled formers, enabling increased spacing between formers while maintaining structural integrity.

Inventive Principle:
Principle #40Composite materials

2Strength

If formers are spaced closer together to maintain stiffness, then structural integrity is improved, but the window width is reduced affecting passenger comfort

Engineering Contradiction:
Improvefuselage stiffnessVSAvoidwindow area
Core Design Contradiction:
StrengthVSArea of stationary object

Solution Approach 1:

By transitioning to a double-walled channel-like former structure, the invention achieves enhanced stiffening in the lateral direction. This allows the formers to be spaced further apart, directly increasing the available window width and area while maintaining the required fuselage stiffness through the improved structural efficiency of the channel configuration.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Area of stationary object

If formers are spaced further apart to increase window width, then passenger comfort is improved, but the stiffness of the fuselage in the lateral direction is reduced

Engineering Contradiction:
Improvewindow areaVSAvoidfuselage lateral stiffness
Core Design Contradiction:
Area of stationary objectVSStrength

Solution Approach 1:

The channel-like cross-section with two walls extending at a spacing creates a structurally efficient configuration that provides superior stiffening capability compared to single-walled formers. This allows increased former spacing for larger windows while maintaining the required lateral stiffness through the enhanced geometric efficiency of the double-walled structure.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The double-walled channel former creates a composite structural system that achieves higher stiffness-to-weight ratio. This composite configuration enables the formers to be spaced further apart for increased window area while the combined structural system maintains the necessary lateral stiffness through the synergistic effect of the two-walled configuration.

Inventive Principle:
Principle #40Composite materials

4Device complexity

If single-walled formers are used, then fewer materials and simpler construction are required, but the stiffening effect on the outer skin is insufficient

Engineering Contradiction:
Improveformer construction complexityVSAvoidouter skin stiffening
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The invention changes the former cross-section from a single-walled to a double-walled channel-like structure. This dimensional change in the cross-sectional geometry provides significantly enhanced stiffening capability for the outer skin, allowing the former to effectively support larger spacing while maintaining structural integrity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

This design increases window width, enhances passenger comfort, and optimizes space for air conditioning components by increasing the spacing between formers, while maintaining structural integrity and reducing thermal and noise impact on air supply.

Implementation Method 1

In order to minimise the influence of the outer skin, which is very cold during flight, on the moderation of the temperature of the supply air conveyed in the air line, it is advisable to dispose an at least thermally insulating material arrangement between the outer skin and the air line.

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP1973776B1Structuring construction for an aircraft fuselage
Publication Date: 2010.06.16 AIRBUS OPERATIONS GMBH
  • EP1973776B1 patent drawingFigure 1~2
  • EP1973776B1 patent drawingFigure 3

AI summary

A structuring construction (10) for an aircraft fuselage comprises an outer skin (12) as well as a plurality of formers (14) extending at a spacing side by side crosswise to the longitudinal direction of the fuselage. According to the invention, at least a partial number of the formers comprise a main former portion (18) which is channel-like in cross section and the channel edges of which are adjacent to the outer skin (12). In a preferred development the channel space of the main former portion (18) serves to accommodate at least one supply air line which may be formed, for example, by a separate pipe line (28).