One-Piece Stiffened Panel Fitting for Composite Junction Gaps

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Stiffened panels in aerospace applications face challenges with weight efficiency and complex assembly processes, particularly when using composite materials, which can compromise structural integrity and lead to rejected junctions due to poor composite quality in tight corners.

Innovation Solution

A one-piece fitting that integrates load transfer between stiffeners and engages with other components, made from materials like aluminum or carbon fiber composites, using additive manufacturing processes, which simplifies assembly and eliminates the need for redundant stiffener material in gaps, thus improving weight efficiency and composite quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If separate mechanical fittings are fastened to stiffeners to transfer load and engage with components, then the structural function is achieved, but the weight efficiency deteriorates

Engineering Contradiction:
Improveweight efficiencyVSAvoidassembly complexity
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The patent merges the load transfer fitting and the mechanical engagement fitting into a single integrated fitting body. This combining of previously separate components eliminates redundant material and simplifies the assembly process, directly addressing the weight efficiency and assembly complexity issues.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated fitting performs multiple functions simultaneously: it transfers load between stiffeners through its body structure and engages with external components through an integral functional fitting. This multi-functionality eliminates the need for separate fittings, reducing overall weight and assembly steps.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Weight of moving object

If composite stiffeners are used to reduce weight, then the weight efficiency improves, but the manufacturing precision deteriorates due to poor composite quality in tight corners

Engineering Contradiction:
Improveweight efficiencyVSAvoidcomposite quality
Core Design Contradiction:
Weight of moving objectVSManufacturing precision

Solution Approach 1:

The patent segments the composite stiffener structure by introducing gaps between adjacent stiffeners. This segmentation eliminates the tight corner regions where composite quality deteriorates, allowing for better manufacturing precision while maintaining the weight efficiency benefits of composite materials.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fitting body acts as an intermediary element that spans the gaps between composite stiffeners. This intermediary structure provides the necessary load transfer function without requiring high-quality composite material in the difficult-to-manufacture tight corner regions.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If redundant stiffener material is placed in gaps to ensure structural integrity, then the strength improves, but the weight efficiency deteriorates

Engineering Contradiction:
Improvestructural integrityVSAvoidweight efficiency
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent combines the load transfer function previously requiring redundant stiffener material with the external engagement function in a single integrated fitting. This eliminates the need for additional stiffener material in gap regions while maintaining structural integrity through the fitting's load transfer capabilities.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3652067B1Fitting for a stiffened panel
Publication Date: 2023.03.08 SAFRAN NACELLES LIMITED
  • EP3652067B1 patent drawingFigure 1
  • EP3652067B1 patent drawingFigure 2~3
  • EP3652067B1 patent drawingFigure 4~5

AI summary

A one-piece fitting (56) for a stiffened panel (51) comprising a panel body (52) with a plurality of stiffeners (53, 54, 55) arranged thereon, the fitting comprising a fitting body (56) configured to be fastened, in use, to two or more of the stiffeners (53, 54, 55) so as to provide a junction to transfer load between the two or more stiffeners, wherein the fitting body further comprises an integral functional fitting (57) arranged for engagement with a component other than the stiffened panel.