Ply Splicing for Composite Charges Spanning Contours
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Solution Overview
Problem
The existing methods for shaping composite charges into complex contours often result in shape discrepancies due to ply slippage during the forming process, leading to undesirable wrinkles and potential discarding of composite parts.
Innovation Solution
Incorporating splice zones within the composite charges, where ply segments are subdivided and overlapped to accommodate slippage, allowing for controlled fiber orientation and stress distribution during shaping, thereby reducing the likelihood of wrinkles and improving the accuracy of the final composite part.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the composite charge is pressed by a mandrel and die to achieve a desired contour, then the composite part attains the required shape, but ply slippage occurs resulting in shape discrepancies and wrinkles
Solution Approach 1:
The patent divides continuous plies into discrete ply segments with splice zones between them. This segmentation allows controlled slippage at the splice zones while maintaining overall shape accuracy, resolving the contradiction between achieving the desired contour and preventing shape discrepancies from ply slippage.
Solution Approach 2:
The patent introduces splice zones at specific locations where plies are joined with overlap or bonding. These localized regions accommodate slippage while the rest of the ply structure maintains its integrity and shape, allowing the composite charge to achieve the desired contour without widespread shape discrepancies.
2Strength
If plies are kept continuous without splicing, then structural integrity is maintained, but slippage during forming causes wrinkles and defects
Solution Approach 1:
By segmenting plies into controlled sections with splice zones, the patent maintains structural integrity through proper splicing techniques while allowing necessary slippage at designated locations to prevent wrinkles, thus resolving the contradiction between strength and reliability.
Solution Approach 2:
The splice zone acts as an intermediary element between ply segments, providing a controlled interface that maintains structural continuity while accommodating slippage. This intermediary structure prevents direct slippage between continuous plies that would cause wrinkles, while still maintaining overall structural integrity.
3Shape
If the composite charge is formed with high curvature, then complex shapes are achieved, but the magnitude of ply slippage increases causing out-of-tolerance discrepancies
Solution Approach 1:
The patent places splice zones strategically in areas of high curvature where slippage is most likely to occur. By segmenting plies at these critical locations, the patent accommodates the increased slippage demands of high-curvature forming while maintaining manufacturing precision through controlled splice design.
Solution Approach 2:
The patent applies different splice zone characteristics at different locations based on the local curvature requirements. Areas of high curvature receive splice zones designed to accommodate greater slippage, while low-curvature areas maintain tighter ply continuity, thus achieving complex shapes while controlling discrepancy magnitude.
4Reliability
If plies are spliced with overlap or gaps, then slippage accommodation is improved, but the complexity of the layup process increases
Solution Approach 1:
While segmentation into ply segments increases layup complexity, the patent provides systematic methods for identifying and positioning splice zones, which manages the complexity through structured procedures rather than arbitrary complications.
Data Source
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AI summary
Systems and methods are provided for designing composite parts. One embodiment is a method for fabricating a composite part. The method includes receiving a design that defines a stacking sequence for a composite charge comprising plies that have different fiber orientations, defining a splice zone within the design, modifying the design by splicing plies in a manner that accommodates ply slippage when the composite charge is formed to a contour, and fabricating a composite part based on the design that was modified.