Integrally Bladed Disk Damping for High-Cycle Fatigue

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Solution Overview

Problem

Integrally bladed rotors (IBRs) in gas turbine engines suffer from high vibratory stresses leading to High Cycle Fatigue (HCF) damage due to lack of mechanical damping, limiting their lifespan.

Innovation Solution

Incorporation of a damper pocket and damper body with a tapered configuration in each rotor blade, along with a plug and weld collar, to provide mechanical damping and reduce vibratory stresses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If integrally bladed rotors are used in gas turbine engines, then the structural integrity and aerodynamic performance are improved, but high vibratory stresses lead to High Cycle Fatigue damage due to lack of mechanical damping

Engineering Contradiction:
Improvestructural integrityVSAvoidresistance to High Cycle Fatigue damage
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent extracts the damping function from separate damping components and integrates it directly into the rotor blade structure through damper pockets and damper bodies. This extraction of the damping function and its integration into the blade structure provides mechanical damping to reduce vibratory stresses while maintaining the structural integrity of the integrally bladed rotor

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs composite structural design by combining the rotor blade material with integrated damper pockets and damper bodies. This composite approach creates a structure that simultaneously provides structural strength and mechanical damping capabilities, addressing both the structural integrity and fatigue resistance requirements

Inventive Principle:
Principle #40Composite materials

2Reliability

If damper pockets and damper bodies with tapered configuration are incorporated in each rotor blade, then mechanical damping and reduction of vibratory stresses are achieved, but the device complexity increases

Engineering Contradiction:
Improvereduction of vibratory stressesVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the damping function with the rotor blade structure by integrating damper pockets and damper bodies directly into each blade. This merging eliminates the need for separate damping components and their associated mounting hardware, thereby reducing overall device complexity while achieving the desired vibratory stress reduction

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The damper pockets and damper bodies serve multiple functions: they provide mechanical damping to reduce vibratory stresses, maintain structural integrity, and can be integrated with the existing rotor blade manufacturing processes. This multi-functionality reduces the need for additional components and simplifies the overall system

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

The solution effectively reduces high vibratory stresses and High Cycle Fatigue damage by dissipating vibrational energy, enhancing the durability and reliability of IBRs.

Implementation Method 1

Incorporation of a damper pocket and damper body with a tapered configuration in each rotor blade, along with a plug and weld collar, to provide mechanical damping and reduce vibratory stresses

Methodology Applied
Scientific EffectMechanical damping: Damping

Data Source

PatentEP4579060A1Integrally bladed disk and rotor blade portion for an integrally bladed disk
Publication Date: 2025.07.02 RTX CORP
  • EP4579060A1 patent drawingFigure 1
  • EP4579060A1 patent drawingFigure 2
  • EP4579060A1 patent drawingFigure 3~4

AI summary

An integrally bladed disk is provided that includes a disk and a plurality of rotor blades (42). The disk has an outer radial hub and is configured for rotation around a rotational axis. Each rotor blade of the plurality of rotor blades has an airfoil (50) that extends chordwise between a leading edge (52) and a trailing edge (54), and extends spanwise between a base end (56) and a blade tip (58). Each rotor blade includes a damper pocket (70), a damper body (72), and a plug (74). The damper pocket extends into the airfoil (50) from the base end and has a first tapered configuration. The damper body is disposed within the damper pocket, and has a second tapered configuration. The second tapered configuration of the damper body mates with the first tapered configuration of the damper pocket . The plug is disposed to retain the damper body within the damper pocket. A rotor blade portion for the integrally bladed disk is also provided that includes the airfoil, the damper pocket and the damper body. The rotor blade portion includes a weld collar (66) affixed to the base end of the airfoil, the weld collar including a weld collar aperture (68) that is aligned with the damper pocket and configured to receive the damper body. The plug is disposed within the weld collar aperture and affixed to the weld collar.