Pre-cured Laminate Rib Assembly for Tiltrotor Wings

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Solution Overview

Problem

The assembly of tiltrotor aircraft wings is complex and labor-intensive due to the need for precise alignment and fastening of numerous components, which increases production time and costs, and requires significant space for fuel and internal systems, while existing methods are inefficient and prone to warping and dimensional issues.

Innovation Solution

A rib assembly for aircraft wings comprising a rib web with pre-cured laminates and a honeycomb panel, attached via skin flanges, which reduces the number of components and simplifies assembly by using fewer fasteners and eliminating the need for I-beam projections, allowing for more space in fuel bays and improved structural support.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If traditional I-beam stringers and multiple reinforcement strips are used, then structural support and stiffness are improved, but the space available for fuel and internal systems is reduced

Engineering Contradiction:
Improvestructural supportVSAvoidfuel bay space
Core Design Contradiction:
StrengthVSVolume of stationary object

Solution Approach 1:

The patent combines multiple separate structural elements (I-beam stringers, reinforcement strips, stiffeners) into an integrated rib assembly with a honeycomb core structure. This merging eliminates the need for protruding I-beam elements while maintaining structural support, thereby increasing fuel bay space.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses thin laminate skins (first and second laminates) combined with a honeycomb core structure to provide structural support. This thin-film approach replaces bulky I-beam stringers, maintaining strength while minimizing space occupation in fuel bays.

Inventive Principle:
Principle #30Flexible shells and thin films

2Strength

If numerous individual components (stringers, reinforcement strips, stiffeners) are assembled, then structural support is improved, but assembly complexity and production time increase

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

Solution Approach 1:

The patent merges multiple separately manufactured components into a single pre-assembled rib assembly unit. This integration reduces the number of parts to be managed and assembled into the wing structure, thereby reducing assembly complexity while maintaining structural support.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The rib assembly is pre-assembled and pre-bonded as a complete unit before installation into the wing. This preliminary assembly action eliminates the need for complex on-site assembly of multiple components, reducing production time and assembly complexity.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If multiple separate components are assembled with numerous fasteners, then structural integrity is improved, but production time and labor intensity increase

Engineering Contradiction:
Improvestructural integrityVSAvoidproduction time
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The rib assembly is pre-bonded as a complete assembly unit before installation. This preliminary bonding action ensures structural integrity is established during manufacturing rather than during final assembly, reducing labor intensity and production time while maintaining reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent combines multiple components into a single pre-bonded assembly, eliminating the need for numerous fasteners during final wing assembly. This merging maintains structural integrity through the bonding process while significantly reducing assembly time and labor requirements.

Inventive Principle:
Principle #5Merging (Combining)

4Strength

If I-beam stringers extend into the wing interior, then stiffness and support are improved, but the space for fuel and internal systems is reduced

Engineering Contradiction:
ImprovestiffnessVSAvoidfuel bay volume
Core Design Contradiction:
StrengthVSVolume of stationary object

Solution Approach 1:

The patent uses thin laminate skins combined with a honeycomb core structure to provide stiffness and support without the bulky I-beam projections. This thin-film approach maintains structural rigidity while maximizing fuel bay volume.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent integrates the stiffening function into the rib assembly structure itself, eliminating the need for separate I-beam stringers extending into the wing interior. This integration maintains stiffness while preserving fuel bay space.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3584066B1Method of making a laminate
Publication Date: 2021.04.14 TEXTRON INNOVATIONS INC
  • EP3584066B1 patent drawingFigure 1~2
  • EP3584066B1 patent drawingFigure 3
  • EP3584066B1 patent drawingFigure 4

AI summary

In one aspect, there is a method of making a pre-cured laminate having a total number of plies in a mold (190), the mold (190) having a periphery (198) defined by a forward edge (198a), an aft edge (198b), and outboard ends (198c, 198d). The method includes selecting a first plurality of resin impregnated plies (173) that continuously extend beyond the periphery (189) of the mold (190), the first plurality of resin impregnated plies (173) includes at least 50 percent of the total number of plies; laying the plies in a mold (190); compacting the plies in a mold (190); and pre-curing the plies to form a pre-cured laminate, which can extend beyond the periphery (198) of the mold (190). In an embodiment, a pre-cured laminate includes a first plurality of resin impregnated plies (173) that continuously extend beyond the periphery (198) of the mold (190), the first plurality of resin impregnated plies (173) includes at least 50 percent of the total number of plies.