Tooling Rod Assemblies for Wrinkle Control in Composite Laminates

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Solution Overview

Problem

Composite laminates formed over tools with irregular geometric shapes or complex curvature often experience uncontrolled wrinkle formation, leading to significant documentation, rework, and potential scrapping of composite articles, resulting in cost and schedule impacts.

Innovation Solution

A wrinkle mitigation system using tooling rod assemblies with elongated tooling rods oriented along directions of wrinkle formation, applied to the tool surface to distribute excess ply material uniformly, forming a corrugated shape when compaction pressure is applied, thereby minimizing uncontrolled pleats and folds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If composite plies are draped over a tool surface with irregular geometric shape or complex curvature, then the composite structure can be formed to match the desired geometry, but excess ply material builds up and causes uncontrolled wrinkle formation

Engineering Contradiction:
Improvecomplex curvatureVSAvoidwrinkle formation
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The tool surface is segmented into multiple zones based on curvature characteristics, with different rod assembly configurations applied to each zone. High curvature regions receive denser rod assemblies while low curvature regions use sparser configurations, allowing localized control of ply distribution to prevent wrinkles in complex geometry areas.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Rod assemblies act as intermediary elements between the tool surface and composite plies. These rods create a controlled corrugated intermediate structure that guides ply material flow and distribution, transforming the uncontrolled draping process into a controlled formation process that eliminates excess material buildup.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If traditional tooling methods are used without wrinkle mitigation, then the fabrication process is simple, but significant rework and scrapping occur due to uncontrolled wrinkle formation

Engineering Contradiction:
Improvefabrication processVSAvoidrework and scrapping
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

Rod assemblies are pre-configured and positioned on the tool surface before composite plies are applied. This preliminary action establishes the corrugated structure that will control ply flow during draping, preventing wrinkle formation before it occurs and eliminating the need for subsequent rework or scrapping operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The rod assembly parameters (rod diameter, spacing, length, and configuration) are optimized to match specific tool surface curvature characteristics. By adjusting these parameters, the system adapts to different geometries while maintaining controlled ply distribution, reducing both fabrication complexity and waste.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If rod width is increased to better control wrinkles, then wrinkle formation is reduced, but the composite ply cannot properly conform to the tool surface in high curvature regions

Engineering Contradiction:
Improvewrinkle controlVSAvoidconformity to tool surface
Core Design Contradiction:
Manufacturing precisionVSShape

Solution Approach 1:

The rod assembly is segmented into multiple rods of varying widths and spacing configurations. Narrower rods are positioned in high curvature regions where fine conformality is needed, while wider rods are used in lower curvature areas where broader wrinkle control is sufficient. This segmentation allows simultaneous achievement of both wrinkle control and surface conformity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different rod widths and spacing densities are applied to different locations on the tool surface based on local curvature requirements. High curvature regions receive finer rod configurations for detailed conformality, while low curvature regions use coarser configurations for efficient wrinkle control, optimizing both shape fidelity and wrinkle prevention.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2914416B1System and method for minimizing wrinkles in composites
Publication Date: 2020.05.06 THE BOEING CO
  • EP2914416B1 patent drawingFigure 1~3
  • EP2914416B1 patent drawingFigure 4~5
  • EP2914416B1 patent drawingFigure 6~7

AI summary

A wrinkle mitigation system may include at least one tooling rod (154) disposed against a tool surface (208) at a location on the tool where a composite ply is configured to overlap the tooling rod. The tooling rod (154) may have an elongated shape and may be generally oriented along a direction of wrinkle formation in the composite ply. The tooling rod may have a rod width that results in the composite ply assuming a corrugated shape when compaction pressure is applied to the composite ply.