Segmented Hoop Tows for Composite Flange Formation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Forming end flanges for composite components, such as fan containment cases, with tri-axial fabric is challenging due to the need for high fabric shear, which often results in increased cost and weight, as traditional methods require more material and compromise structural integrity.

Innovation Solution

Modifying the fabric by separating hoop tows into segments during wrapping, allowing for increased deformation while maintaining structural reinforcement, enabling the formation of features like flanges without eliminating hoop tows, using techniques like stretch breaking or cutting hoop tows at periodic intervals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If traditional methods are used to form end flanges (including recurring linear darts, eliminating hoop tows, or adding separate flange details), then the fabric can be deformed to create flange features, but the cost and weight increase due to requiring more material

Engineering Contradiction:
Improveflange feature formationVSAvoidcomponent weight
Core Design Contradiction:
ShapeVSWeight of stationary object

Solution Approach 1:

The hoop tows are segmented into discrete sections along their length, creating gaps between segments. This segmentation allows the fabric to deform and form flange features while the remaining tow segments provide structural reinforcement, eliminating the need to eliminate entire hoop tow layers or add separate flange details that would increase weight

Inventive Principle:
Principle #1Segmentation

2Shape

If hoop tows are completely eliminated to allow fabric deformation for flange formation, then the fabric can be deformed to create flange features, but the structural integrity is compromised

Engineering Contradiction:
Improveflange feature formationVSAvoidstructural integrity
Core Design Contradiction:
ShapeVSStrength

Solution Approach 1:

The hoop tows have different properties at different locations: segments are created at specific intervals to allow deformation where needed, while the segments between gaps maintain structural integrity. This local differentiation enables flange formation without compromising overall structural strength

Inventive Principle:
Principle #3Local quality

3Shape

If fabric deformation is increased to form complex features like flanges, then the fabric can accommodate complex geometries, but the manufacturing complexity increases

Engineering Contradiction:
Improvefabric deformation capabilityVSAvoidmanufacturing process complexity
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The hoop tows are pre-segmented into sections with gaps between them before the fabric is formed into the final component shape. This preliminary segmentation prepares the fabric to accommodate complex geometries like flanges during forming, reducing the complexity of the actual forming process rather than increasing it

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2794217B1Hoop tow modification for a fabric preform for a composite component
Publication Date: 2020.04.08 GKN AEROSPACE SERVICES STRUTURES LLC
  • EP2794217B1 patent drawingFigure 1
  • EP2794217B1 patent drawingFigure 2
  • EP2794217B1 patent drawingFigure 3

AI summary

A method of forming a fabric preform (20) for a composite component from a fabric (44) having a plurality of hoop tows (46) is disclosed. One end of the fabric (44) is received on the form such that the hoop tows (46) of the fabric (44) extend in a direction generally perpendicular to a central axis of the form. The fabric (44) is wrapped around the form and at least some of the hoop tows (46) are separated into hoop tow segments (87) while the fabric (44) is under a tension to enable a space (100) to develop between ends of adjacent hoop tow segments (87) along the length of the hoop tow (46). This separation of adjacent hoop tow segments (87) accommodates increased deformation of the fabric (44) during formation of the fabric preform (20) while still maintaining a presence of hoop tow segments (87) in at least portions of the fabric (44).