Wavy-Flange Aircraft Structural Assembly for Accessible Fitting Joints
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing aircraft structural assemblies require space for lugs during assembly, limiting usable space and complicating access, while existing configurations do not efficiently distribute load and facilitate inspection, maintenance, and repair.
Innovation Solution
A continuous structural element for aircraft with an inner flange featuring a wavy shape and a fitting with a through hole, allowing the fitting to be joined to the inner flange without covering the web, maximizing space and distributing load effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If lugs are placed outside the inner flange for assembly access, then assembly is possible, but usable space is reduced and device complexity increases
Solution Approach 1:
The fitting is nested within the web space of the continuous structural element, with the through hole positioned inside the web rather than outside the inner flange. This nesting approach allows the fitting to occupy otherwise unused internal space while maintaining assembly access through the web thickness.
Solution Approach 2:
The through hole is repositioned from a two-dimensional plane outside the inner flange to a three-dimensional position within the web thickness. This dimensional change utilizes the z-axis space through the web, freeing up the x-y plane space that would otherwise be occupied by lugs.
2Ease of operation
If lugs are placed outside the inner flange for assembly access, then assembly is possible, but device complexity increases
Solution Approach 1:
The fitting is nested within the web space of the continuous structural element, with the through hole positioned inside the web rather than outside the inner flange. This nesting approach allows the fitting to occupy otherwise unused internal space while maintaining assembly access through the web thickness.
Solution Approach 2:
The through hole is repositioned from a two-dimensional plane outside the inner flange to a three-dimensional position within the web thickness. This dimensional change utilizes the z-axis space through the web, freeing up the x-y plane space that would otherwise be occupied by lugs.
3Strength
If fittings are joined with lugs outside the inner flange, then connection is achieved, but load distribution is concentrated
Solution Approach 1:
The wavy shape of the inner flange creates local variations in web height, allowing the fitting to be positioned at specific locations where load distribution is optimized. The web thickness varies locally to provide both strength at the connection point and broader load distribution across the web structure.
Solution Approach 2:
The wavy shape of the inner flange introduces curvature and undulation to the otherwise flat structure. This curvature allows the web thickness to vary smoothly, creating a gradient that distributes stress more effectively compared to a straight, uniform web configuration.
4Strength
If web covers the through hole for structural integrity, then structural integrity is maintained, but inspection and maintenance become difficult
Solution Approach 1:
The through hole is extracted from the traditional position outside the inner flange and repositioned within the web space. This extraction allows the hole to remain structurally integrated while providing access pathways for inspection and maintenance activities through the web thickness.
Solution Approach 2:
The web itself acts as an intermediary medium that both protects the through hole (maintaining structural integrity) and provides access to it (enabling inspection and maintenance). The wavy shape of the inner flange creates channels or pathways through the web that facilitate this dual function.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Assembly (1) comprising a continuous structural element (2) for aircraft and a fitting (7), wherein: - the continuous structural element (2) for aircraft comprises an outer flange (3), an inner flange (4) and a web (5) between the outer flange (3) and the inner flange (4), the inner flange (4) have having at least one portion with a wavy shape (6) such that the height of the web (5) increases or decreases in the at least one portion of the web (5) corresponding to the at least one portion of the inner flange with a wavy shape (6), and - the fitting (7) comprises at least one through hole (8) and is configured to fit one portion of the web (5) corresponding to one portion of the inner flange (4) with a wavy shape (6), such that in an assembled state the fitting (7) is joined to the portion of the web (5) corresponding to one portion of the inner flange (4) with a wavy shape (6) by connecting means, in such a way that the at least one through hole (8) of the fitting (7) is not covered by the web (5).