Prediction of Vibration Response Levels of Mistuned Integral Bladed Disks (Blisks): Robustness Studies

Integral bladed disks (also known as blisks) are more widely used in modern aeroengine compressor designs because of the potential weight savings, but there are challenges in controlling the extreme vibration response levels in mistuned blisks, which are blisks with blades slightly different from each other. As blisks lack the uncertainty and variability of friction properties related to joints, the maximum vibration response level of a blisk test piece in operation can be predicted prior to installation. A previously proposed response-level prediction procedure for mistuned blisks is outlined, and its robustness is studied. A method of improving the results, given noisy experimental data, is proposed. Some of the issues discussed are validated by using experimental data.