The Amplification of Vibration Response Levels of Mistuned Bladed Disks: Its Consequences and Its Distribution in Specific Situations

Abstract

It is known that small differences between nominally identical turbomachine blades, known as mistuning, can lead to significant variation in their vibration response levels. A commonly used term in mistuning studies called the “amplification factor” is clearly defined in this paper, and the high sensitivity of high-cycle-fatigue-related fatigue life to the level of vibration response levels is presented. Computer simulations are run to study the distribution of the amplification factor in three situations, namely, (i) bladed disks with damping mistuning, (ii) EO excitation of bladed disk modes in the veering region, and (iii) apparently tuned bladed disks. In addition to running simulations, the upper bound of the adjusted amplification factor in damping-mistuned bladed disks is derived theoretically.