Blade-Loss-Caused Rubbing Dynamic Characteristics of Rotor-Bladed Disk-Casing System

摘要

Considering the elastic supports,the finite element model of rotor-bladed disk-casing system is estab-lished using commercial software ANSYS/LS-DYNA.Assuming that broken blade is released from the disk,the complicate rubbing responses of unbalanced rotor-bladed disk-casing system are studied under different operational speeds.In addition,influences of both plastic deformation of blade and casing failure are analyzed.The results show that there exist some multiple even fractional frequencies in the transient and steady vibration responses of unbalanced rotor.Besides,one nodal diameter vibration of bladed disk coupling with the lateral vibration of the shaft as well as the first order bending vibration of blade can be excited under low operational speed,while the first order bending vibration of blade coupling with the lateral vibration of disk-shaft is easily excited under high opera-tional speed.During rubbing process,three distinct contact states can be observed:broken blade-casing contact, broken blade-blade component-casing contact and broken blade-casing contact/blade component-casing contact/blade self-contact.It is worth noting that the third contact state is related to the operational speed.With the in-crease of operational speed,self-contact in the blade may occur.