Parametric Blending and FE-Optimisation of a Compressor Blisk Test Case

Due to raising demands from aviation industry concerning weight reduction and increased efficiency, compressor front stages of jet engines are designed as blade integrated disks (blisks). However, a major drawback of blisks is that small cracks from foreign object impacts occurring in service may propagate into the whole disk causing burst at worst case which is unacceptable. As a damaged blade of a blisk cannot easily be replaced, there is a need for repair. For example, borescope blisk blending may be applied on-wing to ensure safe on-going operation. To determine best solutions for the blending shape, process integration and optimisation tools are used which modify a parametric model and examine its impact on fatigue criteria by FEM.