Thermoplastic Interlocking Grid for Flight Control Surfaces

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Solution Overview

Problem

Current aircraft flight control surface structures, such as GRID-LOCK, are inefficiently manufactured from aluminum billets, requiring lengthy processes and resulting in heavy, high-cost components, whereas thermoplastic materials offer lighter, tougher alternatives but are not effectively utilized in interlocking grid structures for flight control surfaces.

Innovation Solution

A thermoplastic interlocking grid structure method involving spars, ribs, and skins, where ribs interlock with spars at a perpendicular angle via notches and grooved structures, and are fastened using welding or adhesive bonding, allowing for automated fabrication and reduced material usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If aluminum billets are used to manufacture flight control surface structures, then structural strength is achieved, but manufacturing time increases and weight increases

Engineering Contradiction:
Improvestructural strengthVSAvoidmanufacturing time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The flight control surface structure is divided into discrete modular components (spars, ribs, skins) that can be independently manufactured and then assembled through interlocking mechanisms, replacing the monolithic aluminum billet approach and enabling parallel manufacturing processes

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs composite material construction with thermoplastic spars, ribs, and skin panels that provide sufficient structural strength while enabling more efficient manufacturing processes compared to traditional aluminum billet machining

Inventive Principle:
Principle #40Composite materials

2Strength

If aluminum billets are used to manufacture flight control surface structures, then structural strength is achieved, but component weight increases

Engineering Contradiction:
Improvestructural strengthVSAvoidcomponent weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

By segmenting the structure into thin skin panels and lightweight internal spars and ribs connected through interlocking mechanisms, the design achieves structural strength through the composite action of multiple lightweight components rather than a single heavy piece

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The use of composite materials with high strength-to-weight ratio allows the structure to maintain required strength while significantly reducing component weight compared to solid aluminum construction

Inventive Principle:
Principle #40Composite materials

3Strength

If traditional aluminum-based structures are used, then structural integrity is maintained, but manufacturing complexity increases

Engineering Contradiction:
Improvestructural integrityVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

Segmenting the structure into standardized modular components with consistent interlocking mechanisms simplifies manufacturing by enabling repetition of the same connection processes and facilitating automated assembly, despite the multi-component nature

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The spars and ribs are pre-formed with integrated interlocking features (notches, grooves) during manufacturing, and skin panels are pre-drilled with alignment holes, enabling rapid assembly without complex field operations

Inventive Principle:
Principle #10Preliminary action

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 method enables the efficient and lightweight fabrication of flight control surfaces using thermoplastic materials, reducing manufacturing time and weight while maintaining structural integrity, thus addressing the inefficiencies of traditional aluminum-based structures.

Implementation Method 1

The plurality of spars, the plurality of ribs, the first skin, and the second skin may include a thermoplastic material

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

at least one of fillet welding, adhesive bonding, spot ultrasonic welding, or continuous ultrasonic welding

Methodology Applied
Scientific EffectUltrasonic welding: Ultrasonic Vibration

Data Source

PatentEP4344998A1Thermoplastic interlocking grid structure for flight control surfaces
Publication Date: 2024.04.03 ROHR INC
  • EP4344998A1 patent drawingFigure 1A~1B
  • EP4344998A1 patent drawingFigure 2
  • EP4344998A1 patent drawingFigure 3

AI summary

A manufacturing method is provided. A first end of a set of spars (80) is coupled to a first skin (74) of a flight control surface. A set of ribs (90) is interlocked with the set of spars (80) and a first end of the set of ribs (90) is coupled to the first skin (74). A second skin (72) is coupled to a second end of the set of spars (80) and a second end of the set of ribs (90).