Composite Turbine Blade Reinforcing Sheet for Rigidity and Mass Reduction

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Solution Overview

Problem

Turbine engine blades face challenges in achieving optimal rigidity, mass reduction, cost efficiency, and geometry optimization while maintaining mechanical and thermal resistance, particularly due to limitations in impact resistance and overall rigidity from existing reinforcement methods.

Innovation Solution

A composite blade design featuring a reinforcing sheet with constant thickness extending from the leading edge to the trailing edge, integrated within the blade's body, which forms the intrados and extrados surfaces, and is made of different materials such as metallic reinforcement and polymer-filled fibers, enhancing structural integrity and lightness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a metal reinforcement is added to the blade, then the rigidity and impact resistance improve, but the mass increases

Engineering Contradiction:
ImproverigidityVSAvoidmass
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent applies composite materials by combining a metal reinforcing sheet with a polymer matrix composite body. The metal sheet provides rigidity and structural support, while the polymer composite maintains lightness. This composite structure resolves the contradiction by integrating two materials with complementary properties - the metal reinforcement delivers the needed strength without requiring a solid metal blade, thus avoiding excessive mass increase.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The reinforcing sheet is strategically placed at the leading edge where mechanical stress and impact forces are most intense. This localized reinforcement provides maximum rigidity where needed while keeping the rest of the blade lightweight. The sheet extends through the body thickness at the leading edge but does not require full-blade metal construction, optimizing the strength-to-weight ratio.

Inventive Principle:
Principle #3Local quality

2Reliability

If skins are added to external surfaces for protection, then the erosion resistance improves, but the mass increases

Engineering Contradiction:
Improveerosion resistanceVSAvoidmass
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent embeds the metal reinforcing sheet within the polymer matrix composite body, nesting the reinforcement inside the blade structure rather than adding external skins. The sheet passes through the body thickness and is integrated into the blade's internal architecture. This nested configuration provides protection and rigidity without adding external layers that would increase mass and alter the blade's external aerodynamic geometry.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Strength

If a thick leading edge reinforcement is used, then the impact resistance improves, but the geometry optimization and mass are compromised

Engineering Contradiction:
Improveimpact resistanceVSAvoidgeometry
Core Design Contradiction:
StrengthVSShape

Solution Approach 1:

The patent uses a thin metal sheet as the reinforcing element rather than a thick reinforcement structure. The sheet has sufficient strength to provide impact resistance while maintaining a thin profile that does not significantly alter the blade's external geometry. The sheet is embedded within the polymer composite, allowing the external surfaces to maintain their optimized aerodynamic shapes without bulky reinforcements.

Inventive Principle:
Principle #30Flexible shells and thin films

Data Source

PatentEP3064708B1Composite vane of an axial turbine-engine compressor with a reinforcing sheet and turbomachine with comprising such a vane
Publication Date: 2019.10.02 SAFRAN AERO BOOSTERS SA
  • EP3064708B1 patent drawingFigure 1~2
  • EP3064708B1 patent drawingFigure 3~4
  • EP3064708B1 patent drawingFigure 5

AI summary

The invention relates to a composite blade (26) for a low-pressure axial turbomachine compressor. The blade (26) comprises a platform (30), an aerodynamic blade (34) with a leading edge (38) and a trailing edge (40). The blade (34) extends into the primary flow of the turbomachine. The blade (34) has a body (36) extending from the leading edge (38) to the trailing edge (40) and a leading-edge reinforcement (42). The reinforcement (42) includes a reinforcing sheet (70) extending from the leading edge (38) to the trailing edge (40) and arranged within the thickness of the body (36) to strengthen it. Furthermore, the reinforcement includes a shell (46) forming the leading edge (38) and which is integral with the sheet (70). The blade (70) is a titanium sheet, and the body (36) comprises an organic matrix composite material reinforced with fibers. This configuration improves rigidity and corrosion resistance while reducing the weight of the blade (26).Turbomachine including such a blade.