Bladed Rotor Repair Evaluation with Structural and Aerodynamic Criteria

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Solution Overview

Problem

Current repair methods for integrally bladed rotors (IBRs) in gas turbine engines are limited, as they fail to consider functional assessment criteria such as aerodynamic stability and structural durability, leading to unnecessary scrapping of damaged rotors without exploring more optimal repair options.

Innovation Solution

A method involving digital representation of a repaired bladed rotor, generated from inspection data, which includes performing structural and aerodynamic simulations to determine if the repair meets experience-based criteria like modal assurance criteria, resonant frequency, and aerodynamic efficiency, allowing for informed repair decisions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional geometric assessment constraints are applied to damaged IBRs, then the inspection and repair process is simplified, but functional assessment constraints such as aerodynamic stability and structural durability are not considered, leading to unnecessary scrapping

Engineering Contradiction:
Improveease of repair assessmentVSAvoidfunctional assessment accuracy
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent combines geometric assessment constraints (tolerances, material removal/addition volumes) with functional assessment constraints (aerodynamic stability, structural durability) into a unified repair analysis system. This merging allows simultaneous evaluation of both geometric compliance and functional performance, preventing unnecessary scrapping of IBRs that meet functional criteria even if they exceed traditional geometric tolerances.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The repair analysis system is designed to perform multiple assessment functions simultaneously: geometric tolerance checking, aerodynamic stability analysis, and structural durability evaluation. This multi-functional approach replaces the need for separate assessment processes and enables comprehensive repair decision-making based on both geometric and functional criteria.

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

2Productivity

If geometric assessment constraints are used for repair decisions, then the repair process is faster and simpler, but optimal repair options that could maintain aerodynamic or structural capability are missed

Engineering Contradiction:
Improverepair decision speedVSAvoidrepair option flexibility
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The system performs preliminary functional assessments during the repair analysis phase, evaluating aerodynamic stability and structural durability before final repair decisions are made. This preliminary functional evaluation identifies potential repair options that maintain performance criteria, allowing repair practitioners to explore more flexible repair approaches while still ensuring functional adequacy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The repair analysis system dynamically evaluates multiple repair scenarios by adjusting geometric parameters and assessing their impact on functional performance. This dynamic analysis allows the system to adapt to different repair configurations and identify optimal solutions that balance geometric constraints with functional requirements, rather than applying fixed geometric tolerances.

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If damaged IBRs are scrapped based on geometric constraints without functional assessment, then quality control is maintained, but cost-effective repair opportunities are lost

Engineering Contradiction:
Improvegeometric tolerance controlVSAvoidmaterial waste
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The system changes the assessment parameters from purely geometric tolerances to include functional performance metrics. By evaluating aerodynamic stability and structural durability as primary criteria, the system allows greater geometric variability in repaired IBRs while maintaining quality control through functional performance verification, thereby reducing material waste and enabling cost-effective repairs.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4257801A1Repair analysis systems and methods for inspected bladed rotors
Publication Date: 2023.10.11 RTX CORP
  • EP4257801A1 patent drawingFigure 1A
  • EP4257801A1 patent drawingFigure 1B
  • EP4257801A1 patent drawingFigure 2~4

AI summary

A system and method comprises generating, via a processor (602), a digital representation of a portion of a repaired bladed rotor (170), the digital representation based on geometrical dimensions determined from an inspection of an inspected bladed rotor (100) and a repair blend profile (162, 166, 168) for a defect of the inspected bladed rotor (100), performing, via the processor (162), a structural simulation on a structural model, the structural model based on the digital representation of the repaired bladed rotor (170), performing, via the processor (162), an aerodynamic simulation on an aerodynamic model, the aerodynamic model based on the digital representation of the repaired bladed rotor (170), determining, via the processor (162), whether results from the structural simulation and the aerodynamic simulation meet an experience based criteria for the repaired bladed rotor (170), and repairing the inspected bladed rotor in response to determining the criteria is met.