Composite Multispar Torsion Box Integration

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current manufacturing methods for composite material torsion boxes in the aeronautical industry are inefficient due to high production costs, weight penalties, and non-uniform load distribution, as they require multiple assembly steps and mechanical fasteners, despite efforts towards integration.

Innovation Solution

A method involving the stacking and bending of composite material layers with integrated stiffeners, followed by a single pressure and temperature cycle using unidirectional fiber strips (rovings) to form a fully integrated multispar torsion box structure, reducing the number of parts and enhancing load uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If structural elements are manufactured separately and mechanically joined with complicated jigs, then assembly tolerances can be achieved, but weight penalties increase and production complexity increases

Engineering Contradiction:

Improveassembly tolerancesVSAvoidweight penalties

Core Design Contradiction:

Manufacturing precisionVSWeight of moving object

Solution Approach 1:

The patent merges multiple structural elements (spars, ribs, stringers) into a single integrated torsion box structure manufactured from one continuous composite laminate. This eliminates the need for mechanical fasteners and complicated joining operations, thereby removing weight penalties while maintaining assembly tolerances through monolithic construction.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces mechanical joining systems (fasteners, jigs, assembly fixtures) with a continuous composite laminate structure that achieves precise tolerances through the manufacturing process itself. The composite material's inherent properties and the molding process substitute for mechanical assembly systems, eliminating associated weight and complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If structural elements are manufactured separately and mechanically joined, then assembly can be performed in multiple steps, but production costs increase and productivity decreases

Engineering Contradiction:

Improvemanufacturing processabilityVSAvoidproduction efficiency

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent combines multiple manufacturing steps into a single integrated process where the entire torsion box structure is manufactured in one continuous operation. This eliminates repeated setup, tooling changes, and quality inspections associated with multi-step assembly, thereby improving productivity while maintaining ease of manufacture through a streamlined process.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of manufacture

If multiple assembly stations and joining elements are used, then structural elements can be connected, but device complexity increases and logistic capacity requirements increase

Engineering Contradiction:

Improveassembly capabilityVSAvoidassembly system complexity

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the need for multiple assembly stations, complicated jigs, and numerous joining elements by manufacturing the entire torsion box as a single integrated structure. This removes the complex assembly system while preserving the capability to connect structural elements through the monolithic construction process.

Inventive Principle:

Principle #2Taking out (Extraction)

4Strength

If mechanical fasteners are used for joining elements, then structural connections can be achieved, but aerodynamic quality of outer surfaces deteriorates

Engineering Contradiction:

Improvestructural connection strengthVSAvoidaerodynamic quality

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent merges all structural elements into a continuous composite laminate that forms smooth, uninterrupted outer surfaces. This eliminates mechanical fasteners that would create surface discontinuities, thereby maintaining aerodynamic quality while achieving structural connection strength through the integrated laminate construction and resin bonding.

Inventive Principle:

Principle #5Merging (Combining)

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 results in a cost-effective, lightweight, and aerodynamically superior integrated structure with improved load distribution and reduced manufacturing complexity, achieving the necessary strength and rigidity for aircraft components.

Implementation Method 1

consolidating the complete structure by means of applying a single pressure and temperature cycle

Methodology Applied

Scientific EffectCuring:

Data Source

PatentEP2153979B1Multispar torsion box made from composite material

Publication Date: 2016.10.19 AIRBUS OPERATIONS SL

Figure 1~2b
Figure 2c
Figure 3~5

AI summary

The invention relates to an integrated multispar torsion box structure of composite material for aircraft, comprising a lower skin (12), an upper skin (11), several spars (9), each of which comprises in turn a chord (13) and a web (14), several stringers (10) in the lower skin (12) and several stringers (10) in the upper skin (11), characterized in that the mentioned integrated torsion box structure is achieved by means of joining unitary U-shaped structural elements (15), unitary U-shaped structural elements (16) with a flap and unitary C-shaped structural elements (17) with a flap. The invention also relates to a method for manufacturing an integrated multispar torsion box structure of composite material for aircraft.