Aircraft Panel Edge Closeout Using Segmented Trim

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Solution Overview

Problem

Existing edge closeout techniques for sandwich panels in aircraft are labor-intensive and costly, adding significant weight while failing to provide an aesthetically pleasing, radiused edge finish.

Innovation Solution

A layered panel structure with a polymer or composite core and face sheets, where a trim piece with a trim member and flange member is connected to create a flush edge closeout that is aesthetically desirable and reduces weight by hiding the trim piece behind the face sheet.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If the 'ditch and pot' edge closeout technique is used, then the edge closeout is sharp and non-radiused which is aesthetically desired, but the technique is labor intensive and expensive, and also adds significant weight

Engineering Contradiction:
Improveedge sharpnessVSAvoidaircraft weight
Core Design Contradiction:
ShapeVSWeight of moving object

Solution Approach 1:

The trim piece is divided into two functional segments: a trim member that provides the visible sharp edge profile and a flange member that provides structural attachment. This segmentation allows each part to be optimized for its specific function while reducing overall material requirements compared to the ditch and pot technique.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The trim piece is positioned and attached within the recess formed by the protruding face sheet edge, nesting the closeout solution within the existing panel structure rather than adding external material layers, thereby reducing weight.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Shape

If the 'ditch and pot' edge closeout technique is used, then the edge closeout is sharp and non-radiused which is aesthetically desired, but the technique is labor intensive and expensive

Engineering Contradiction:
Improveedge sharpnessVSAvoidmanufacturing complexity
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The trim piece is pre-formed with the desired sharp edge profile and attachment features before installation. The recess in the face sheet is also pre-formed during panel manufacturing, allowing the trim piece to be simply attached rather than requiring labor-intensive on-site fabrication and finishing operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The trim piece is made from a simple extruded or molded profile that can be mass-produced at low cost, replacing the expensive custom fabrication and multi-step finishing process required by the ditch and pot technique.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Weight of moving object

If a trim piece is connected to the protruding portion to cover the first edge, then the edge closeout is aesthetically pleasing and reduces weight, but the trim piece must be integrated seamlessly with the panel structure

Engineering Contradiction:
Improveaircraft weightVSAvoidpanel structure complexity
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The flange member of the trim piece serves multiple functions: it provides structural attachment to the panel, distributes loads across the recess area, and maintains the aesthetic profile. This multi-functionality reduces the need for additional separate components, simplifying the overall structure despite the added closeout feature.

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

Data Source

PatentEP3144125B1Panel and associated closeout method
Publication Date: 2019.06.19 THE BOEING CO
  • EP3144125B1 patent drawingFigure 1
  • EP3144125B1 patent drawingFigure 2
  • EP3144125B1 patent drawingFigure 3~4

AI summary

A panel (10) having a layered structure (12) including a core (20) defining a first edge (27) and a face sheet (22) connected to the core (20), the face sheet (22) including a protruding portion (33) defining a second edge (31), wherein the second edge (31) protrudes outward a distance (D) from the first edge (27), and a trim piece (14) connected to the layered structure (12), the trim piece (14) including a trim member (40) and a flange member (42) extending from the trim member (40), the trim member (40) defining a visible surface (48) and a trim edge (50), wherein the trim member (40) is positioned over the first edge (27), wherein the trim edge (50) is connected to the protruding portion (33), and wherein the flange member (42) is connected to the opposite side of the layered structure (12), with respect to the face sheet (22).