Segmented Hoop Tows for Composite Flange Preform Forming
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Solution Overview
Problem
Forming end flanges for composite components like fan containment cases with tri-axial fabric is challenging due to the need for high fabric shear, which often requires additional material and increases cost and weight, compromising structural integrity.
Innovation Solution
Modifying hoop tows in the fabric to be separable into segments during wrapping, allowing for increased deformation while maintaining structural reinforcement, enabling the formation of features like flanges without eliminating hoop tows.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional methods are used to form end flanges (including recurring linear darts, eliminating hoop tows, or adding separate flange details), then the structural integrity of the flange is maintained, but the cost and weight increase due to additional material requirements
Solution Approach 1:
The fabric is divided into multiple plies with different tow configurations. Specifically, the first ply contains hoop tows that provide structural reinforcement, while the second ply contains bias tows that enable deformation. This segmentation allows the flange region to achieve both strength and deformability without adding extra material.
Solution Approach 2:
Different regions of the fabric are given different properties to meet local requirements. The flange region has a specific ply configuration where hoop tows are present in the first ply for strength, while bias tows in the second ply allow for the necessary deformation. This local differentiation eliminates the need for uniform reinforcement throughout the entire component.
2Adaptability or versatility
If hoop tows are eliminated to allow fabric deformation for forming flanges, then the deformation capability is improved, but the structural reinforcement is compromised
Solution Approach 1:
The fabric is segmented into multiple plies with distinct functions. The first ply contains hoop tows that maintain structural reinforcement, while the second ply contains bias tows that provide deformation capability. This segmentation resolves the contradiction by assigning different properties to different layers rather than requiring the entire fabric to have both properties simultaneously.
Solution Approach 2:
The fabric uses a composite structure with multiple plies having different tow orientations and properties. The combination of hoop tows in one ply with bias tows in another ply creates a composite material system where the strengths of individual components are preserved while enabling overall deformation capability through the interaction between plies.
3Strength
If additional material is added to reinforce flanges separately, then the structural integrity is improved, but the cost increases
Solution Approach 1:
Instead of adding separate flange details or recurring linear darts, the invention segments the fabric into plies where the flange reinforcement is integrated into the base fabric structure. The hoop tows in the first ply and bias tows in the second ply work together to provide both strength and deformability, eliminating the need for additional reinforcing material.
Solution Approach 2:
The multi-ply fabric structure serves multiple functions simultaneously. The same fabric plies that provide structural reinforcement for the cylindrical body also provide the necessary deformation capability for forming flanges. This multi-functionality eliminates the need for separate reinforcing elements and reduces overall material usage.
Data Source
AI summary
A method of forming a fabric preform for a composite component from a fabric having a plurality of hoop tows is disclosed. One end of the fabric is received on the form such that the hoop tows of the fabric extend in a direction generally perpendicular to a central axis of the form. The fabric is wrapped around the form and at least some of the hoop tows are separated into hoop tow segments while the fabric is under a tension to enable a space to develop between ends of adjacent hoop tow segments along the length of the hoop tow. This separation of adjacent hoop tow segments accommodates increased deformation of the fabric during formation of the fabric preform while still maintaining a presence of hoop tow segments in at least portions of the fabric.