3D Woven CMC Turbine Blade Platform for Lower Interlaminar Stress

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Solution Overview

Problem

Ceramic Matrix Composite (CMC) turbine blades face challenges in attaching a platform due to low interlaminar strengths, leading to high internal interlaminar stresses and limited functionality, as the combined load of the overhung platform and damper causes large bending stresses at the blade root region.

Innovation Solution

A method involving a ceramic matrix composite blade with a separate airfoil/root assembly and a three-dimensional platform assembly, where the platform is bonded to the airfoil and root portion using a three-dimensional woven preform to distribute loads and reduce interlaminar tensile stresses, utilizing a silicon interfacial layer for bonding and incorporating complex weave patterns for enhanced strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a platform is attached to a laminated CMC blade, then the platform can support blade-to-blade dampers and form the inner flowpath, but the low interlaminar strengths of CMC cause high internal interlaminar stresses that limit the platform's functionality and lifespan

Engineering Contradiction:
Improveplatform functionalityVSAvoidinterlaminar strength
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent employs a three-dimensional woven CMC architecture where fibers are interlaced in multiple directions (0°, 90°, and ±45° orientations) to create a complex load-bearing structure. This 3D woven composite material provides superior interlaminar strength compared to traditional laminated CMC, enabling the platform to support dampers and form the inner flowpath without suffering from high internal interlaminar stresses.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If the platform is cantilevered from the blade root, then it can protect the rim from hot gas ingestion, but the combined load of the overhung platform and damper creates large bending stresses at the platform-blade root junction

Engineering Contradiction:
Improvehot gas protectionVSAvoidbending stress
Core Design Contradiction:
Object-affected harmful factorsVSStress or pressure

Solution Approach 1:

The patent transitions from a traditional 2D laminated platform structure to a 3D woven architecture that extends in multiple spatial dimensions. The three-dimensional fiber reinforcement distributes bending stresses more effectively throughout the platform volume, reducing peak stresses at the critical platform-blade root junction while maintaining the cantilevered configuration needed for hot gas protection.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The use of 3D woven CMC with multi-directional fiber orientations (including ±45° layers) creates a composite structure that is specifically optimized to resist bending loads. The complex fiber architecture provides enhanced stiffness and strength in multiple directions, allowing the cantilevered platform to better withstand the combined loads of its own weight and attached dampers.

Inventive Principle:
Principle #40Composite materials

3Strength

If CMC blades use layers of cloth or unidirectional tape, then they achieve good strength in the primary radial load path, but attaching a platform becomes difficult due to low interlaminar strengths

Engineering Contradiction:
Improveradial load strengthVSAvoidplatform attachment
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent replaces traditional laminated CMC construction with 3D woven CMC material. This 3D woven composite maintains the excellent radial load strength of unidirectional tapes while providing superior interlaminar strength through the interlaced fiber architecture. The enhanced interlaminar properties enable reliable platform attachment through bonding or mechanical fastening without compromising the blade's primary load-bearing capability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent separates the blade into distinct functional regions: the airfoil and root portion maintain their traditional CMC construction optimized for radial loads, while the platform is constructed from 3D woven CMC specifically engineered for high interlaminar strength. This segmentation allows each component to be optimized for its specific function while ensuring compatible attachment interfaces.

Inventive Principle:
Principle #1Segmentation

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 approach optimizes the structural performance of CMC blades by minimizing interlaminar tensile stresses, increasing the interlaminar tensile strength, and allowing for complex features, thereby extending the platform's functionality and reducing bending stresses in the root region.

Implementation Method 1

utilizing a silicon interfacial layer for bonding

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP2540965B2Manufacturing method for a ceramic fiber reinforced ceramic composite component with internal three-dimensionally woven platform and corresponding component
Publication Date: 2022.02.16 RTX CORP
  • EP2540965B2 patent drawingFigure 1
  • EP2540965B2 patent drawingFigure 2
  • EP2540965B2 patent drawingFigure 3

AI summary

A method of forming a component (10) for use in a gas turbine engine includes the steps of forming an airfoil/root assembly (12, 14); creating a platform assembly structure (24) having an opening (30); inserting the airfoil/root assembly (12, 14) into the opening (30); and bonding the platform assembly structure (24) to the airfoil/root assembly (12, 14) to form the component (10). A component (10) is also provided.