Pi-Section Composite Reinforcement for Turbomachine Fan Platforms

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Solution Overview

Problem

Existing methods for manufacturing reinforcement parts with a π-section, particularly for turbomachine fan platforms, face challenges in achieving sufficient stiffness and preventing buckling due to centrifugal forces, while also requiring complex folding and multiple positioning of fibrous blanks.

Innovation Solution

A method involving three-dimensional weaving of two sets of layers of threads to form a base and stiffener preforms, where the threads are bonded along a central unbinding strip that flares out at the base's step zone, allowing for the formation of legs without folds and simplifying the shaping process, and subsequent matrix densification to create a robust composite reinforcement part.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If complex folding and multiple positioning of fibrous blanks are used to form stiffener legs, then the mechanical properties and stiffness are improved, but the manufacturing complexity and difficulty increase significantly

Engineering Contradiction:
Improvestiffness of stiffener legsVSAvoidmanufacturing process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention applies preliminary action by pre-forming the stiffener legs directly during the three-dimensional weaving process itself, rather than requiring subsequent folding and positioning operations. The weaving process creates the leg geometry in advance, eliminating the need for complex post-processing steps while maintaining the required mechanical properties and stiffness of the stiffener legs.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention merges the formation of the base and stiffener legs into a single integrated three-dimensional weaving operation. Instead of separately manufacturing components and assembling them through folding and positioning, the entire reinforcing piece with both base and stiffener legs is created in one continuous weaving process, significantly simplifying the manufacturing workflow while ensuring proper mechanical integration.

Inventive Principle:
Principle #5Merging (Combining)

2Strength

If traditional manufacturing methods with folding and multiple positioning are used, then the mechanical properties can be achieved, but the risk of folds and buckling increases

Engineering Contradiction:
Improvemechanical propertiesVSAvoidrisk of buckling
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

By pre-forming the stiffener legs during the three-dimensional weaving process, the invention eliminates subsequent folding operations that would create potential buckling points. The legs are created in their final geometric configuration during weaving, ensuring proper fiber alignment and eliminating the risk of folds and buckling that would compromise structural reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention converts the potential harm of complex manufacturing operations (which introduce folds and buckling risks) into a benefit by using the three-dimensional weaving process itself to directly create the leg geometry. This approach transforms what would be a harmful multi-step folding process into a beneficial single-step weaving process that inherently produces the desired shape without defects.

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

3Strength

If three-dimensional weaving of the entire reinforcing piece in one piece is used, then the mechanical properties are improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvemechanical propertiesVSAvoidweaving process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention applies segmentation by dividing the three-dimensional weaving process into two separate operations: first weaving the base portion, then weaving the stiffener legs. This segmentation allows each component to be optimized for its specific geometry and fiber orientation requirements, while the final assembly is achieved through simple positioning and bonding operations, reducing overall manufacturing complexity compared to attempting to weave the entire complex geometry in one operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses preliminary action by completing the base weaving first, then adding the stiffener legs in a subsequent weaving operation. This sequential approach allows each weaving operation to be optimized for its specific component, and the preliminary base structure serves as a foundation for the subsequent leg attachment, simplifying the overall manufacturing process while maintaining high mechanical properties.

Inventive Principle:
Principle #10Preliminary action

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 mechanical properties of turbomachine fan platforms by preventing buckling and simplifying the manufacturing process, ensuring robustness and correct positioning of stiffener legs, while maintaining the advantages of composite materials like thermostructural composites.

Implementation Method 1

the threads of the second set of layers of threads are bonded to the threads of the first set of layers of threads along a central unbinding strip extending longitudinally between the two longitudinal ends of the first part of fibrous blank

Methodology Applied
Scientific EffectWeaving:

Implementation Method 2

depositing a resist do in the fibrous preform to obtain a composite material reinforcement part having a fibrous reinforcement constituted by the preform and densified by the matrix

Methodology Applied
Scientific EffectMatrix densification:

Implementation Method 3

The centrifugal force due to the rotation of the fan also tends to bulge the platform at its center

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP2802702B1Pi-section reinforcing piece made of composite material, notably turbomachine fan platform, and method of manufacturing same
Publication Date: 2018.12.26 SAFRAN AIRCRAFT ENGINES SAS
  • EP2802702B1 patent drawingFigure 1
  • EP2802702B1 patent drawingFigure 2~4
  • EP2802702B1 patent drawingFigure 5~7

AI summary

The invention relates to a method of manufacturing a pi-section reinforcing piece (10) made of composite material, the method involving using three-dimensional weaving to create a first set of layers of threads which layers are joined together to form a first fibrous rough form part (102) intended to form a base preform, using three-dimensional weaving to create a second set of layers of threads which layers are joined together to form a second fibrous rough form part (104) intended to form a stiffener preform, threads of the second set being connected by weaving to the threads of the first set along a central disconnection strip (106) that widens towards the lateral edges (102a) of the first fibrous rough form part in a region (108, 110) corresponding to the step of the base, shaping the two fibrous rough form parts to obtain a fibrous preform (100) in a single piece that has a part forming the base preform and a part forming a stiffener preform, and applying a resin to the fibrous preform using a die. The invention also relates to a pi-section reinforcing piece obtained using the method.