Analysis of Random Vibration for Mistuned Bladed Disk

When calculating the vibratory response of bladed turbine disks, it is assumed that all blades on a given disk are identical. This leads to the prediction that all blades experience the same amplitude. However, it has been shown experimentally that significant variations in these amplitudes occur for different blades on the same disk. These variations arise due to the effects of mistuning, which refers to small differences in blade characteristics. Although the mistuning effect on the resonant response has been studied systematically, few papers have researched the mistuning effect on the random vibration. This paper, first, presents the analysis method of the mistuning effect on the random vibration. Second, the mistuning analyses for the random vibration and the resonant vibration of the bladed turbine disk are carried out, and the both results are compared. From these results, the mistuning effect on the random vibration is clarified.