Transient amplitude amplification of mistuned structures: An experimental validation

Abstract

Until now, only few works have dealt with the transient vibration response of bladed disks of turbomachinery. However, transient vibration of turbines has become more and more important due to the changes on the energy production sector. Recently, it has been theoretically demonstrated that the maximum amplitude of the resonance passage of mistuned blisks may even exceed the maximum amplitude of the steady-state response. This effect is called transient amplitude amplification of mistuned structures (TAMS). The phenomenon is investigated within this article. By using a lumped mass model, it is shown how the maximum amplitude of the steady-state solution may be exceeded by the maximum amplitude of the resonance passage. Further, the occurrence of transient amplitude amplification of mistuned structures is experimentally validated.A new experimental set-up is designed to perform a resonance passage. Hence, an accelerated traveling wave type excitation is created. Loudspeakers are used to perform a contactless excitation. With the designed test rig, the occurrence of TAMS can be demonstrated. The results are the first experimental proof that the maximum of a transient vibration response can exceed the maximum of the stationary vibration response of the same dynamic system.