Contoured Forming Head for Concave Composite Prepreg Compaction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Manual manipulation of prepreg plies to conform to concave tool surfaces is time-consuming, costly, and prone to non-uniform pressure application, leading to variations in ply thickness and operator fatigue in composite part fabrication.

Innovation Solution

A forming apparatus with a forming head that matches the contour of the concave mandrel, equipped with a handle for ergonomic manipulation and optional heating, allows for precise compaction of prepreg plies using force and strain gauges to ensure uniform pressure application.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual manipulation is used to conform prepreg plies to concave tool surfaces, then the operator can directly control the forming process, but operator fatigue increases and fabrication time is excessive

Engineering Contradiction:

Improvemanual controlVSAvoidfabrication time

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

A forming apparatus with a forming head matching the concave tool surface contour is introduced as an intermediary between the operator and the prepreg ply. The apparatus includes a handle for ergonomic manipulation and a forming head that contacts and conforms the ply to the cavity, reducing direct manual manipulation while maintaining control.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The forming head is designed to automatically conform to the concave tool surface contour through its matching geometry, allowing the apparatus itself to perform the conforming action rather than requiring continuous operator intervention to shape each ply manually.

Inventive Principle:

Principle #25Self-service

2Ease of operation

If manual manipulation is used to conform prepreg plies, then flexibility in handling is maintained, but uniformity of pressure application deteriorates

Engineering Contradiction:

Improvehandling flexibilityVSAvoidply thickness uniformity

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The forming head is manufactured with an outer surface that precisely matches the local contour of the concave cavity interior surface. This localized geometric matching ensures uniform pressure distribution across the entire ply surface, addressing variations in cavity curvature while maintaining handling flexibility through the handle design.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent replaces inconsistent manual mechanical pressure application with a standardized forming head geometry that ensures uniform pressure distribution. The forming head's contoured surface mechanically translates operator force into uniform compaction across the ply, eliminating variations caused by manual dexterity limitations.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If traditional plastic sweep tools are used, then simple tooling is available, but effectiveness in conforming plies to concave surfaces is insufficient

Engineering Contradiction:

Improvetool simplicityVSAvoidconforming accuracy

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The forming head is manufactured with an outer surface that precisely matches the local contour of the concave cavity interior surface. This localized geometric matching ensures uniform pressure distribution and accurate conforming to complex curved surfaces, significantly improving upon the flat or uniformly curved geometry of traditional sweep tools.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The forming head's geometry parameters are specifically tailored to match the cavity contour parameters, including curvature radii and surface profiles. This parameter matching enables the tool to effectively conform plies to concave surfaces that traditional sweep tools cannot accommodate due to their fixed, non-matching geometry.

Inventive Principle:

Principle #35Parameter changes

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 apparatus efficiently and uniformly conforms prepreg plies to concave tool surfaces, reducing fabrication time and costs while minimizing operator fatigue and ply thickness variations, resulting in high-quality composite parts with consistent properties.

Implementation Method 1

The placed prepreg ply is then optionally heated with a heating element that can be incorporated in the forming apparatus instead of a stand-alone device. Once the prepreg ply is optionally heated to a predetermined temperature

Methodology Applied

Scientific EffectHeating: Heating

Data Source

PatentUS10081140B2Apparatus for and method of compaction of a prepreg

Publication Date: 2018.09.25 THE BOEING CO

AI summary

A forming apparatus and method of using the apparatus with a concave mandrel to form composite materials is presented where the apparatus has a forming head with an outer surface having a contour that matches the interior surface of the concave cavity of a matching mandrel. A handle and a grip surface to allow an operator to use the forming apparatus to exert a compaction force to successive plies of prepreg to conform the laminate of plies to the interior surface of the concave cavity. Each ply is heated before contact with the forming head of the apparatus.