Undulated Composite Forming Tools for Controlled Wrinkle Patterns

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Solution Overview

Problem

Forming composite structures without undesirable wrinkles is challenging due to the difficulty in conforming flexible sheets to tools with varying curvatures, leading to wrinkles that are difficult to remove and require additional manufacturing steps.

Innovation Solution

Using tools with curved regions featuring undulations that impart a desired wrinkle configuration to the conformable material, reducing or eliminating undesirable wrinkles by distributing material into acceptable micro-wrinkles or dimples.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If a planar sheet of composite material is conformed to a tool with varying curvatures, then the composite structure can be formed with complex geometry, but undesirable wrinkles are imparted to the material

Engineering Contradiction:

Improvecomplex geometryVSAvoidwrinkle-free surface

Core Design Contradiction:

ShapeVSManufacturing precision

Solution Approach 1:

The tool surface is pre-configured with undulations that correspond to the desired wrinkle pattern. These undulations are formed into the tool before the composite material is applied, so that when the material is conformed to the tool, the wrinkles are already in their intended locations and configurations, eliminating the need for post-processing removal of unwanted wrinkles

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Instead of trying to prevent wrinkles entirely (which is difficult when conforming to complex curvatures), the invention accepts that wrinkles will form and deliberately designs the tool undulations to convert the harmful random wrinkles into beneficial controlled micro-wrinkles. The undulations guide the material to form wrinkles in specific patterns that meet performance requirements

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Ease of manufacture

If traditional forming methods are used without undulated tools, then the manufacturing process is simpler, but additional steps and tools are required to remove undesirable wrinkles

Engineering Contradiction:

Improveforming processVSAvoidmanufacturing cycle time

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The desired wrinkle configuration is predetermined and built into the tool surface through undulations before the forming process begins. This preliminary configuration eliminates the need for subsequent wrinkle removal steps, reducing the total number of manufacturing operations and decreasing cycle time

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention extracts the wrinkle removal operation from the manufacturing process by preventing unwanted wrinkles from forming in the first place. The undulated tool surface ensures that only acceptable micro-wrinkles are formed, eliminating the need for separate wrinkle removal steps and associated tools

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentEP4516474B1Methods and tools for forming composite structures with preferable wrinkle configurations

Publication Date: 2026.04.22 THE BOEING CO

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AI summary

Methods and tools for forming a composite structure with a desired wrinkle configuration are disclosed herein. An example method includes shaping a composite material using a tool. In some examples, the shaping comprises forming a desired wrinkle configuration in the conformable material. An example tool for forming a composite structure includes a curved region comprising undulations in at least one portion of the curved region, the undulations configured such that when a conformable material is draped over the curved region, a desired wrinkle configuration is imparted to the conformable material.