Composite Stringer Gap Filler Layup Using Notched Forming Dies

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The manual and labor-intensive process of placing gap fillers in composite parts, particularly for stringers extending several feet, is inefficient and time-consuming, affecting the production of structural components for aircraft.

Innovation Solution

A forming system with specially shaped dies and a robot arm is used to automatically place gap fillers on flat charges before shaping, utilizing notches in male dies to retain and adhere gap fillers during the formation of preforms, ensuring precise placement without compression or distortion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If gap fillers are manually placed along the preform, then structural strength is enhanced, but labor time and production efficiency deteriorate

Engineering Contradiction:

Improvestructural strengthVSAvoidlabor time

Core Design Contradiction:

StrengthVSLoss of time

Solution Approach 1:

The gap filler is placed on the flat charge before shaping into preform, rather than placing after preform creation. This preliminary action allows automated robot arm placement on the flat, accessible surface, dramatically reducing labor time while maintaining the structural strength benefit of gap filler placement at internal corners

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Manual mechanical placement by workers is replaced with an automated robot arm system that can precisely place gap filler material. The robot arm dispenses and positions the gap filler material automatically, converting a labor-intensive manual process into an automated manufacturing process that reduces labor time while maintaining placement accuracy

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If gap fillers are placed on flat charge before shaping, then placement accuracy is improved, but device complexity increases

Engineering Contradiction:

Improveplacement accuracyVSAvoiddevice complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The forming process is segmented into distinct stages: flat charge preparation with gap filler placement, shaping into preform, and final assembly. The tooling is also segmented with specific male and female dies designed for the flat charge configuration. This segmentation allows gap filler placement to occur at the simplest stage (flat charge) before complex shaping, improving placement accuracy without requiring the entire system to be overly complex

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The flat charge serves as an intermediary medium that facilitates easy gap filler placement. By placing the gap filler on the flat, two-dimensional charge rather than on the complex three-dimensional preform, the process achieves high placement accuracy. The flat charge acts as a convenient substrate that simplifies the placement operation while still achieving the ultimate goal of proper gap filler positioning in the final product

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If conventional shaping dies are used, then manufacturing simplicity is maintained, but gap filler compression and distortion occur

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidgap filler positioning

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The male and female dies are designed with specific local features adapted to the flat charge configuration and gap filler presence. The dies have appropriate clearances, surface characteristics, and shaping zones that account for the gap filler material placed on the flat charge. This localized adaptation of the tooling ensures that shaping occurs without excessive compression or distortion of the gap filler, maintaining positioning precision while keeping the manufacturing process simple

Inventive Principle:

Principle #3Local quality

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

This method enhances the ease and accuracy of gap filler application, reducing labor time and ensuring structural integrity by maintaining gap fillers in precise positions during the formation of preforms, which are then integrated with skin preforms for enhanced structural strength.

Implementation Method 1

the female dies include suction ports configured to apply suction that holds the flat charge during forming of the flat charge

Methodology Applied

Scientific EffectSuction: Suction

Data Source

PatentEP4067058B1Application of gap fillers during layup of charges of composite material

Publication Date: 2026.04.22 THE BOEING CO

Figure 1
Figure 2
Figure 3

AI summary

Systems and methods are provided for shaping flat charges (120). One example is a forming system for shaping a flat charge (120). The forming system includes female dies (130) that are elongate and are configured to hold the flat charge (120), and a male die (110) that is elongate and is configured to press into the flat charge (120) between the female dies (130) to form the flat charge (120) while the flat charge (120) is supported, the male die (110) includes notches (114) that extend along a length of the male die (110) and are dimensioned to retain gap fillers (122) of the flat charge (120) at widthwise locations (124) of the flat charge (120) corresponding to corners (132) at the female dies (130) while the flat charge (120) is formed.