Numerical Investigation on The Effect of Geometrical Mistuning on Forced Response Vibration of a Blisk

This paper presents a numerical investigation of the forced response vibration of an integrally bladed disk known as blisk, in both tuned and mistuned conditions. For this purpose, a full finite element model is considered for the tuned structure. Then the length of each blade is changed randomly and applied to the blisk structure to generate mistuned blisk. By applying base excitation to the structures, the worst response of each structure has been extracted using ANSYS 17.2 software. The worst response is occurring where there is the maximum value of deflection in the structure. Also, the frequency response function of each single cantilever blade is studied in tuned and mistuned manner. The scattering of the first bending frequency response function has been extracted and compared. Also, the amount of deviation of the worst response in mistuned blisk was calculated and the susceptible location of damage and failure in the mistuned blisk was identified. The findings show that small geometrical deviations in blades, in addition to increasing the level of vibrations, can result in the emergence of new phenomena in the shapes of mistuned blisk vibrations, increasing the risk of crack initiation and propagation due to high cycle fatigue.