Gas Turbine Blade Localized Stiffening via Recessed Composite Fill

Solution Overview

Problem

Gas turbine engine blades deform elastically due to aerodynamic forces, leading to high cycle fatigue and poor aerodynamic performance, particularly in geared fans with low rotational speeds and reduced tip speeds.

Innovation Solution

Localized stiffening of blades is achieved by creating recesses in their surfaces and filling them with materials of higher stiffness, such as composite materials, to enhance the blades' structural integrity and reduce unwanted deflections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If the blade is made more flexible to reduce weight, then weight is reduced, but blade deflection increases leading to high cycle fatigue and poor aerodynamic performance

Engineering Contradiction:

Improveblade weightVSAvoidblade stiffness

Core Design Contradiction:

Weight of moving objectVSStrength

Solution Approach 1:

The patent applies local quality by creating recesses in specific regions of the blade and filling them with stiffer material. This provides localized stiffening at critical areas (such as the blade root or sections experiencing high bending moments) while keeping the rest of the blade lightweight. The stiffer material is strategically placed to counteract elastic deformation without requiring the entire blade to be heavier.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining the base blade material with a stiffer filler material in the recesses. This creates a composite structure where the two materials work together - the base material provides overall structural integrity and weight efficiency, while the stiffer filler material provides localized reinforcement to reduce deflection and prevent fatigue.

Inventive Principle:

Principle #40Composite materials

2Strength

If the blade is made stiffer to reduce deflection, then blade stiffness is improved, but weight increases

Engineering Contradiction:

Improveblade stiffnessVSAvoidblade weight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The patent applies local quality by creating recesses in specific regions of the blade and filling them with stiffer material. This provides localized stiffening at critical areas (such as the blade root or sections experiencing high bending moments) while keeping the rest of the blade lightweight. The stiffer material is strategically placed to counteract elastic deformation without requiring the entire blade to be heavier.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining the base blade material with a stiffer filler material in the recesses. This creates a composite structure where the two materials work together - the base material provides overall structural integrity and weight efficiency, while the stiffer filler material provides localized reinforcement to reduce deflection and prevent fatigue.

Inventive Principle:

Principle #40Composite materials

3Strength

If material is added to stiffen the blade, then blade stiffness is improved, but manufacturing complexity increases

Engineering Contradiction:

Improveblade stiffnessVSAvoidmanufacturing complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the blade into distinct regions - areas with recesses and areas without. This allows the manufacturing process to be broken into manageable steps: creating recesses in specific locations, then filling only those recesses with stiffer material. This segmented approach is simpler than attempting to uniformly stiffen the entire blade or use complex composite layup patterns throughout.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by creating recesses in specific regions of the blade and filling them with stiffer material. This provides localized stiffening at critical areas (such as the blade root or sections experiencing high bending moments) while keeping the rest of the blade lightweight. The stiffer material is strategically placed to counteract elastic deformation without requiring the entire blade to be heavier.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS8241003B2Systems and methods involving localized stiffening of blades

Publication Date: 2012.08.14 RTX CORP

AI summary

Systems and methods involving localized stiffening of blades are provided. In this regard, a representative a gas turbine engine blade includes: a recess located in a surface of the blade; and material positioned at least partially within the recess such that the material provides a localized increase in stiffness of the blade.