Rotatable Tray Drape Forming Apparatus for Composite Flange Wrinkle Control

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Solution Overview

Problem

Uncontrolled compression during hot drape forming of composite materials often results in buckling or wrinkling of plies, leading to defects in composite parts, particularly in aerospace applications where precise shaping is critical.

Innovation Solution

A drape forming apparatus with a pressurized bladder and a rotatable tray system, where a resistance device controls the rate of rotation to apply uniform pressure, preventing wrinkles and ensuring consistent formation of composite structures with flange portions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If composite material is forced around a mandrel with vacuum bag or pressurized bladder, then composite parts can be formed for aerospace applications, but uncontrolled compression results in buckling or wrinkling of plies

Engineering Contradiction:
Improvecomposite part formationVSAvoidply integrity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The tray is made rotatable about a pivot line, transforming from a static to a dynamic system. This allows the tray to rotate during the forming process, enabling controlled material flow and pressure distribution that prevents buckling and wrinkling while maintaining manufacturing efficiency

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The resistance device dynamically adjusts the rate of rotation of the tray, changing the temporal parameter of the forming process. By controlling rotation speed, the system optimizes both material formation quality and defect prevention, resolving the contradiction between ease of manufacture and manufacturing precision

Inventive Principle:
Principle #35Parameter changes

2Shape

If pressurized bladder applies force to form composite structure, then shaping is achieved, but uncontrolled compression causes defects in flange portions

Engineering Contradiction:
Improvecomposite structure formationVSAvoiddefect-free flange
Core Design Contradiction:
ShapeVSReliability

Solution Approach 1:

The rotatable tray introduces dynamic motion to the forming process. As the tray rotates at a controlled rate, it distributes the compressive force from the pressurized bladder more evenly across the flange portion, preventing localized over-compression that causes defects while maintaining the desired shape

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The resistance device provides feedback control by adjusting the rotation rate based on the forming process requirements. This closed-loop control ensures that pressure is applied at the optimal rate, maintaining both shape accuracy and reliability by preventing defect formation

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system enables more reliable, defect-reduced, and uniform formation of composite structures by controlling pressure and rotation, enhancing the quality of composite parts in aerospace and other applications.

Implementation Method 1

The pressurized bladder is configured to induce a first force against the tray such that the tray rotates about a pivot line

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 2

a resistance device coupled to said tray, said resistance device configured to provide a second force that opposes the first force to control a rate of rotation of said tray

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

heating one or more plies of flat pre-impregnated (i.e., prepreg) composite material, and forcing the composite material around a mandrel

Methodology Applied
Scientific EffectThermal softening: Heating

Data Source

PatentEP3196006B1Apparatus and method of forming a composite structure
Publication Date: 2021.01.06 THE BOEING CO
  • EP3196006B1 patent drawingFigure 1
  • EP3196006B1 patent drawingFigure 2~3
  • EP3196006B1 patent drawingFigure 4~5

AI summary

A drape forming apparatus (202) for use in forming a composite structure is provided. The apparatus includes a forming tool (212) including an upper forming surface (214) and at least one side forming surface (216) that extends from the upper forming surface. The forming tool is configured to receive at least one layer (218) of composite material extending over the upper forming surface. The apparatus also includes a flange forming device (200, 228, 238, 244, 248) including a tray (206, 230, 240) coplanarly aligned with the upper forming surface when in a first operating position. The tray is configured to receive a flange portion (222) of the at least one layer of composite material. A pressurized bladder (226) extends over the forming tool and the tray. The pressurized bladder is configured to induce a first force against the tray such that the tray rotates about a pivot line (208), and such that the flange portion is withdrawn from the tray and draped over the at least one side forming surface.