Modeling of Integrally Bladed Rotor (IBR) Blends

Integrally bladed rotors (IBR), also called blisks, are becoming increasingly common in the compressor and fan sections of modern turbine engines. The integration of the blades and disks into a single part has the advantages of reduced part count, reduced weight, increased reliability, and increased performance. However, a drawback of this technology is that individual blades cannot be easily replaced and thus blending is typically used to resolve minor damage to blades. Blending involves removing material around the damaged area to reduce the stress concentrations that could lead to cracking and subsequent failure. But this process also changes the mechanical, dynamic, and aerodynamic properties of the blisk. This project will combine the expertise of Simmetrix, Duke University and GE to create a system to model the effects of introducing blends into a blisk, giving the ability to accurately predict the structural and aerodynamic effects of such a repair. By being able to model these effects, the blend shape and size can be optimized minimizing the impacts on the performance and reliability of the engine.