Considering the elastic supports,the finite element model of rotor-bladed disk-casing system is established using commercial software ANSYS/LS-DYNA.Assuming that broken blade is released from the disk,the complicate r...Considering the elastic supports,the finite element model of rotor-bladed disk-casing system is established 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 operational 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 selfcontact.It is worth noting that the third contact state is related to the operational speed.With the increase of operational speed,self-contact in the blade may occur.展开更多
The finite element models of blade, disk and bladed disk are built up by finite element software ANSYS. The natural frequencies of the single blade, the whole bladed disk and the bladed disk with only one sector by cy...The finite element models of blade, disk and bladed disk are built up by finite element software ANSYS. The natural frequencies of the single blade, the whole bladed disk and the bladed disk with only one sector by cyclic symmetry boundary have been calculated. Then, based on the results above, a structure dynamic model of multiple degree-of-freedom （MDOF） systems is established to simulate the bladed-disk assembly. Solve the motion equation by using the Runge-Kutta Method （Gill Method）. The dynamic response of the MDOF system is achieved. As for the given mistuning patterns, the vibration responses of bladed disks are calculated. The results have been compared and analyzed, and the optimum pattern is selected.展开更多
An efficient multi-harmonic method is proposed for studying the effects of mistuning on resonant features of bladed disks with blade-to-blade dry friction damping. This method is able to predict accurately the forced ...An efficient multi-harmonic method is proposed for studying the effects of mistuning on resonant features of bladed disks with blade-to-blade dry friction damping. This method is able to predict accurately the forced response of bladed disks in frequency domain, which is validated by numerical integration method in time domain. The resonant features of both tuned and mistuned systems are investigated by using this method under various system coupling strengths, viscous dampings, and dry friction darnpings, etc. The results demonstrate that the proposed multi-harmonic method is very efficient for studying the mistuning effects on the resonant response of bladed disks with blade-to-blade dry friction damping, especially considering the combined effects of various system parameters.展开更多
基金supported by the National Natural Science Foundation of China(No.11772089)the Fundamental Research Funds for the Central Universities (Nos. N160312001and N160313004)the Research Project of State Key Laboratory of Mechanical System and Vibration(No.MSV201707)
文摘Considering the elastic supports,the finite element model of rotor-bladed disk-casing system is established 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 operational 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 selfcontact.It is worth noting that the third contact state is related to the operational speed.With the increase of operational speed,self-contact in the blade may occur.
文摘The finite element models of blade, disk and bladed disk are built up by finite element software ANSYS. The natural frequencies of the single blade, the whole bladed disk and the bladed disk with only one sector by cyclic symmetry boundary have been calculated. Then, based on the results above, a structure dynamic model of multiple degree-of-freedom （MDOF） systems is established to simulate the bladed-disk assembly. Solve the motion equation by using the Runge-Kutta Method （Gill Method）. The dynamic response of the MDOF system is achieved. As for the given mistuning patterns, the vibration responses of bladed disks are calculated. The results have been compared and analyzed, and the optimum pattern is selected.
基金National Nature Science Foundation of China (NO.50275121)
文摘An efficient multi-harmonic method is proposed for studying the effects of mistuning on resonant features of bladed disks with blade-to-blade dry friction damping. This method is able to predict accurately the forced response of bladed disks in frequency domain, which is validated by numerical integration method in time domain. The resonant features of both tuned and mistuned systems are investigated by using this method under various system coupling strengths, viscous dampings, and dry friction darnpings, etc. The results demonstrate that the proposed multi-harmonic method is very efficient for studying the mistuning effects on the resonant response of bladed disks with blade-to-blade dry friction damping, especially considering the combined effects of various system parameters.
