Composite Multi-Spar Box Continuous Skin Manufacturing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional aircraft tail cone section assembly methods require heavy interface fittings that concentrate loads, leading to weight penalties, increased drag, and complex assembly processes, with existing solutions failing to provide a seamless load transmission and efficient manufacturing process.

Innovation Solution

A manufacturing process for a composite multi-spar box with a continuous skin upper shell, integrating a trumpet-shaped part with a u-shaped part using advanced fibre placement and hot forming, eliminating the need for interface fittings by directly joining the vertical and horizontal tail plane skins to the fuselage skin.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If interface fittings are used to join the vertical tail plane to the fuselage, then load transmission is achieved, but weight increases and drag increases due to fittings and fairings

Engineering Contradiction:
Improveload transmissionVSAvoidweight of fittings
Core Design Contradiction:
ForceVSWeight of moving object

Solution Approach 1:

The patent merges the vertical tail plane skin directly with the fuselage skin to form a continuous load-bearing surface. The interface fittings, fairings, and separate structural elements are eliminated by creating an integrated monolithic structure where the tail plane skin flows continuously into the fuselage skin, achieving both weight reduction and smooth aerodynamic surfaces

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent extracts and removes the interface fittings and aerodynamic fairings from the conventional assembly. By taking out these separate components and replacing them with a continuous skin structure, the invention eliminates the weight penalty and drag associated with discrete fittings and their covering fairings

Inventive Principle:
Principle #2Taking out (Extraction)

2Force

If interface fittings are used to join the vertical tail plane to the fuselage, then load transmission is achieved, but aerodynamic drag increases due to fairings

Engineering Contradiction:
Improveload transmissionVSAvoidaerodynamic drag
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The patent merges the vertical tail plane skin directly with the fuselage skin to form a continuous load-bearing surface. The interface fittings, fairings, and separate structural elements are eliminated by creating an integrated monolithic structure where the tail plane skin flows continuously into the fuselage skin, achieving both weight reduction and smooth aerodynamic surfaces

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent extracts and removes the interface fittings and aerodynamic fairings from the conventional assembly. By taking out these separate components and replacing them with a continuous skin structure, the invention eliminates the weight penalty and drag associated with discrete fittings and their covering fairings

Inventive Principle:
Principle #2Taking out (Extraction)

3Strength

If conventional assembly methods with multiple parts and fittings are used, then structural integrity is achieved, but assembly complexity and production time increase

Engineering Contradiction:
Improvestructural integrityVSAvoidassembly complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent merges the vertical tail plane skin directly with the fuselage skin to form a continuous load-bearing surface. The interface fittings, fairings, and separate structural elements are eliminated by creating an integrated monolithic structure where the tail plane skin flows continuously into the fuselage skin, achieving both weight reduction and smooth aerodynamic surfaces

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The manufacturing process segments the fabrication into manageable stages (forming the tail plane, forming the fuselage section, joining them) while achieving an integrated final structure. This allows complex monolithic components to be manufactured and assembled in a systematic way that reduces overall complexity

Inventive Principle:
Principle #1Segmentation

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 approach reduces weight, assembly complexity, and aerodynamic drag by allowing smooth load transmission, enhancing damage tolerance and reducing production lead time and costs, while eliminating the need for heavy fittings and their associated fairings.

Implementation Method 1

heating the thermoplastic composite material above its glass transition temperature

Methodology Applied
Scientific EffectGlass transition:

Implementation Method 2

deforming the thermoplastic composite material with a forming tool

Methodology Applied
Scientific EffectThermal deformation:

Implementation Method 3

pressing the thermoplastic composite material against a cooling surface

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3584152B1Method for manufacturing a multi-spar box with a continuous skin upper shell of a tail cone section for a rear end of an aircraft and a composite assembly
Publication Date: 2023.06.07 AIRBUS OPERATIONS SL
  • EP3584152B1 patent drawingFigure 1A~1B
  • EP3584152B1 patent drawingFigure 2~3
  • EP3584152B1 patent drawingFigure 4A~4B

AI summary

Examples herein relate to a method for manufacturing a composite assembly with a continuous skin for a rear end of an aircraft by obtaining an upper part (405) of the rear end by composite tooling. The upper part comprises a multi-spar vertical tail plane. The spars (410) of the vertical tail plane comprise widening roots that form an upper shell of the rear end and an upper skin (425). Furthermore, a lower part (415) comprises a lower shell of the rear end including semi-complete frames (420) and stringers and a lower skin (430). The upper and lower parts are assembled with a joining procedure. The upper and lower skins are joined to obtain the composite assembly with the continuous skin.