Composite Turbomachine Blade Reinforcement With Variable Ply Profiles

Solution Overview

Problem

Existing composite turbomachine blades face challenges with high stress levels at the blade root area, inadequate local reinforcement, and insufficient stiffness, leading to increased mass and risk of buckling, particularly in unducted turbomachines with complex geometries and 3D woven organic matrix composites.

Innovation Solution

A reinforcement system for composite turbomachine blades is introduced, comprising a stack of plies with varying lengths and widths, arranged to match the complex geometry of the blade's inner cavity, providing enhanced mechanical strength and stiffness while minimizing mass impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the blade dimensions are increased to improve bypass ratio and performance, then the mass of the blade increases, but this increases the mass of the blade which is detrimental to performance

Engineering Contradiction:

Improvebypass ratioVSAvoidblade mass

Core Design Contradiction:

ProductivityVSWeight of moving object

Solution Approach 1:

The blade is constructed using composite materials consisting of fiber reinforcement (such as carbon fibers) embedded in an organic matrix (such as epoxy resin). This composite structure allows the blade to achieve high strength-to-weight ratio, providing the necessary mechanical strength for larger blade dimensions while minimizing mass. The fibrous reinforcement provides structural integrity and the organic matrix binds the fibers together, creating a lightweight yet strong composite material that resolves the contradiction between size and weight.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The blade design incorporates local reinforcement at critical areas such as the blade root and leading edges, where stress concentrations occur. By adding reinforcement only where structurally necessary rather than uniformly throughout the entire blade, the design maintains lightweight construction while providing enhanced strength and stiffness at load-bearing zones. This localized approach to reinforcement reduces overall mass while addressing specific structural requirements.

Inventive Principle:

Principle #3Local quality

2Strength

If the blade root area is reinforced to reduce stress levels, then the mass of the blade increases, but this increases the mass which is detrimental to performance

Engineering Contradiction:

Improveblade root strengthVSAvoidblade mass

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The blade design incorporates local reinforcement at critical areas such as the blade root and leading edges, where stress concentrations occur. By adding reinforcement only where structurally necessary rather than uniformly throughout the entire blade, the design maintains lightweight construction while providing enhanced strength and stiffness at load-bearing zones. This localized approach to reinforcement reduces overall mass while addressing specific structural requirements.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The blade is constructed using composite materials consisting of fiber reinforcement (such as carbon fibers) embedded in an organic matrix (such as epoxy resin). This composite structure allows the blade to achieve high strength-to-weight ratio, providing the necessary mechanical strength for larger blade dimensions while minimizing mass. The fibrous reinforcement provides structural integrity and the organic matrix binds the fibers together, creating a lightweight yet strong composite material that resolves the contradiction between size and weight.

Inventive Principle:

Principle #40Composite materials

3Stability of the object's composition

If the blade is designed with complex geometry to match the inner cavity, then the manufacturing complexity increases, but this improves the structural integrity and stress distribution

Engineering Contradiction:

Improvestructural integrityVSAvoidblade geometry complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The blade design incorporates local reinforcement at critical areas such as the blade root and leading edges, where stress concentrations occur. By adding reinforcement only where structurally necessary rather than uniformly throughout the entire blade, the design maintains lightweight construction while providing enhanced strength and stiffness at load-bearing zones. This localized approach to reinforcement reduces overall mass while addressing specific structural requirements.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20250215800A1Reinforcement for a composite blade of a turbomachine, comprising a stack of plies

Publication Date: 2025.07.03 SAFRAN SA

AI summary

The present application relates to a reinforcement (6) for a blade (1) of a turbomachine (100), the blade (1) comprising a first outer skin (2) and a second outer skin (3) which are made of composite material and each comprise an inner end portion (21, 31) spaced apart from each other in such a way as to delimit therebetween an inner cavity (4) of the blade (1) that opens into an opening (5), wherein the reinforcement (6) is adapted to be arranged in the inner cavity (4) in such a way as to close the opening (5), and wherein the reinforcement (6) comprises a stack of plies (61) that are superposed along a stacking direction (De) corresponding to a thickness direction (Pe) of the plies (61), at least two plies (61) having different lengths (Pl) and/or widths (PL) such that the reinforcement (6) has a profile of variable dimensions.