Blades Vibration Response Study of a Bladed Disk System Connecting with Two Lacing Wires and Mistuning Effect

In order to avoid flutter phenomena in blades of a turbine stage, the blades have not been made equal and they have some differences in their masses and stiffness. These small differences are called mistuning. In this study, the effect of the mistuning on vibration response of blades connecting with two lacing wires is studied. First, the system has modeled by mass-spring-damper and then the governing equations are derived. After that, the vibration response of the mistuned system is compared with the vibration response of the tuned system in the different type of blades numbers connection. The vibration response of the mistuned system is also investigated when all of the blades are connected. The results show that a small change in the stiffness of the tuned system causes the vibration amplitude of some of the blades of the system to change considerably in some of the blades connection arrangements. For example, it can be seen that the mistuning up to about 0.5 percent, in the case of connecting eight blades to each other in a row of turbine blades, increases about 11 percent the amplitude of vibration response of the system.