Integrally Bladed Rotor Stack Repair Using Structural and Aerodynamic Checks
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Solution Overview
Problem
Conventional repair methods for integrally bladed rotors (IBRs) in gas turbine engines are limited by geometric and functional assessment constraints, often leading to scrapping damaged IBRs without considering operational loads and boundary conditions, thereby neglecting more optimal repair options.
Innovation Solution
A method involving finite element modeling, structural and aerodynamic analysis, and iterative repair processes to determine and implement repairs that meet both structural and aerodynamic criteria, allowing for the repair and certification of IBRs for reassembly in gas turbine engines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional geometric assessment constraints are applied for IBR repair, then manufacturing precision is maintained, but productivity is reduced due to excessive scrapping of repairable IBRs
Solution Approach 1:
The patent transitions from purely geometric parameters to include functional parameters (aerodynamic and structural performance) in the repair assessment. This allows IBRs with defects outside geometric tolerances to be repaired and certified if they meet functional criteria, thereby increasing the repair rate while maintaining safety and performance standards.
Solution Approach 2:
The patent implements preliminary functional assessment through finite element modeling and simulation before actual repair. This preliminary action identifies IBRs that can be repaired, allowing planning of repair strategies that maintain geometric precision while maximizing the number of repairable components.
2Reliability
If material removal or addition is performed to repair IBR defects, then reliability is improved by removing defects, but manufacturing precision deteriorates due to altered geometry
Solution Approach 1:
The patent changes the assessment parameters from strict geometric conformity to functional performance-based criteria. IBRs can undergo material removal or addition for defect repair, and as long as the repaired components meet aerodynamic and structural functional criteria, they are certified for service. This resolves the contradiction by prioritizing reliability while accepting geometric variations within functional limits.
Solution Approach 2:
The patent employs iterative finite element analysis and simulation to assess the impact of repair operations on structural and aerodynamic performance. This feedback loop allows optimization of repair strategies to maintain functional performance while accommodating necessary geometric changes for defect removal.
3Reliability
If functional assessment is performed for IBR repair certification, then reliability is improved by considering operational loads, but device complexity increases due to additional analysis requirements
Solution Approach 1:
The patent uses finite element models as digital copies of the physical IBR stack to perform virtual structural and aerodynamic assessments. These computational models replicate the behavior of actual components under operational loads, enabling reliable functional assessment without requiring physical testing of each repaired IBR, thus managing complexity through simulation rather than physical experimentation.
Solution Approach 2:
The patent performs preliminary functional assessment through computational modeling before actual repair and certification. By conducting virtual tests and analyses in advance, the system determines which IBRs can be repaired and what repair strategies will maintain functional performance, reducing the complexity of post-repair verification and certification processes.
Data Source
AI summary
A plurality of potential repair processes for a stack of IBRs may be determined. Each repair process may be associated with a defect on an inspected IBR. A finite element model of the stack of IBRs may be generated to model a potential repaired defect of each inspected IBR. The model may also include a plurality of vane stages disposed between adjacent inspected IBRs and an engine case. A structural analysis and an aerodynamic analysis may be performed. Whether the stack of IBRs with the potential repaired defect meets a structural criteria and an aerodynamic criteria may be determined. Each IBR in the stack of IBRs may be repaired with the repair process for the potential repaired defect for each inspected IBR in the stack of IBRs in response to determining the stack of IBRs meets the structural criteria and the aerodynamic criteria.