Vibration in Mistuned Bladed Circular Disk

Abstract

bladed disk NF=5 is used to explore the impact of localized stiffness on the vibration characteristics of mistuned bladed disks, and the impacts of various stiffness amplitudes along with stiffened areas on the maximum forced response are discussed in this paper. Prototypical bladed-disk structures subjected to finite-element simulation and modal testing show the presence of specific wavenumbers over the base number of nodal diameters that contaminate and continue to degrade the appearance of some doublet modes. In light of a companion perturbation analysis for periodic structures, it is explained how the natural frequency and wavenumber content of such modes varies and splits. Simultaneous measurements with a modal test setup positioned over the structure are used to establish and validate resonance conditions. The findings demonstrate that the highest split of double natural frequencies of each modal family occurs at frequency-veering regions where there are such regions. Along with the response amplitude and polluted wavenumbers, the lower harmonics of the split mode show the area of localized stiffness.