Omega Stringer Tube Core for Balanced Composite Consolidation

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Solution Overview

Problem

Existing hydrostatic membrane press technology (HyM2) cannot scale to larger parts or skins with complex topologies, such as double curvature, and integrating omega stringers is challenging due to pressure imbalances.

Innovation Solution

A flexible omega tube core made of metal, polymer, or elastomer, connected to a pressure balance system, ensures equal pressure application during consolidation or curing, allowing integration of omega stringers on ramped skins.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If hydrostatic membrane press technology is used for consolidation, then consolidation speed and integration are improved, but scalability to larger parts and complex topologies deteriorates

Engineering Contradiction:
Improveconsolidation speedVSAvoidscalability to larger parts and complex topologies
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The consolidation process is segmented into multiple independent inflatable tubes distributed across the workpiece surface. Each tube operates independently to provide localized pressure, allowing the system to scale to larger parts and complex topologies while maintaining high consolidation speed through parallel operation of multiple tubes

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses flexible inflatable tubes with thin walls that can conform to complex surface topologies including double curvature. These flexible shells adapt to the workpiece shape while providing uniform pressure distribution, enabling scalability to larger and more complex parts without sacrificing consolidation effectiveness

Inventive Principle:
Principle #30Flexible shells and thin films

2Strength

If omega stringers are integrated using traditional methods, then structural strength is improved, but manufacturing complexity and cycle time deteriorate

Engineering Contradiction:
Improvestructural strengthVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention merges the omega stringer integration process with the consolidation process by placing inflatable tubes directly inside the stringer hollow sections. This combining of operations allows simultaneous consolidation and stringer integration in a single manufacturing step, reducing device complexity and cycle time while maintaining structural strength through co-curing

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The inflatable tubes are nested inside the hollow sections of the omega stringers during consolidation. This nesting arrangement allows the tubes to expand and provide internal pressure support directly within the stringer structure, enabling integrated manufacturing without additional external fixtures or complex assembly steps

Inventive Principle:
Principle #7Nested doll (Nesting)

3Manufacturing precision

If pressure is applied during consolidation, then consolidation quality is improved, but pressure imbalance and defects deteriorate

Engineering Contradiction:
Improveconsolidation qualityVSAvoidpressure imbalance and defects
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The invention applies local quality by using individually controllable inflatable tubes that can provide pressure distribution tailored to local requirements. Each tube can be pressurized independently based on the specific consolidation needs of its location, ensuring optimal pressure application while preventing defects caused by pressure imbalance

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The inflatable tubes create equipotential pressure distribution across the consolidation surface by expanding to equalize pressure throughout each tube and across multiple tubes. This equipotential approach eliminates pressure imbalances and harmful stress concentrations, improving consolidation quality while preventing defects

Inventive Principle:
Principle #12Equipotentiality

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

Enables reliable quality, reduced material usage, shorter cycle times, and weight savings by ensuring even pressure application, making it scalable to larger parts and skins with complex topologies.

Implementation Method 1

the elongated flexible hollow tube core is pressurizable by a first pressure so that the elongated flexible hollow tube core expands to essentially the same shape as the thermoforming stringer

Methodology Applied
Scientific EffectPressure: Pressure Increase

Data Source

PatentEP4659931A1Thermoforming composite and system for curing or consolidating a thermoforming composite
Publication Date: 2025.12.10 AIRBUS OPERATIONS GMBH
  • EP4659931A1 patent drawingFigure 1
  • EP4659931A1 patent drawingFigure 2A~2B
  • EP4659931A1 patent drawingFigure 3A~3B

AI summary

The present disclosure relates to a thermoforming composite, comprising a thermoforming base layer having a first principal surface and a second principal surface opposing the first principle surface; a thermoforming stringer having a base part and an elongated protruding part, wherein the base part is attached to the first principal surface of the thermoforming base layer to enclose an elongated hollow part between the first principal surface of the thermoforming base layer and the protruding part; and an elongated flexible hollow tube core inserted into the elongated hollow part. During consolidation or curing of the thermoforming base layer and the thermoforming stringer, the elongated flexible hollow tube core is pressurizable by a first pressure so that the elongated flexible hollow tube core expands to essentially the same shape as the thermoforming stringer, a second pressure is a uniform pressure exertable to the second principal surface, and the first pressure is essentially equal to a second pressure.