Effect of creep on the nonlinear vibration characteristics of blades with interlocked shrouds

Abstract In this paper, the influence of creep on the nonlinear vibrations of blades coupled by friction joints is numerically investigated. To this end, a model of a bladed disk with interlocked shrouds is considered. First, the time-dependent creep behavior under centrifugal loading and high temperatures is determined. For a discrete set of hold times, the deformed configuration and the conditions in the contact interfaces are extracted. A nonlinear modal analysis is then carried out to determine the amplitude-dependent damping and natural frequencies under consideration of the dynamic contact interactions in the shroud joints. It is found that for a given excitation level, the resonance frequency and the effective damping can deviate considerably from the initial ones. Moreover, the overall damping potential is slightly reduced.