Study on Vibration of the Anisotropically Rotor System with Different Sections Based on the Improved Riccati Transfer Matrix Method

Author(s):  
Pang Guoying ◽  
Chen Yushu ◽  
Cao Shuqian ◽  
Li Bo
2011 ◽  
Vol 35 (1) ◽  
pp. 81-100
Author(s):  
Chao-Yang Tsai ◽  
Shyh-Chin Huang

In this paper, a transfer matrix method (TMM) for rotors with multiple coupler offsets was derived. The studies showed the coupler’s stiffness altered the rotor’s critical speeds but offset caused additional external excitation. The cases of two offsets in- and anti-phase in a typical rotor were given as examples. In the in-phase case, significantly increased response amplitude occurred at lower rotational speed and the increase was linearly proportional to the offset value. As to the anti-phase case, the increased response was insignificant, implying an opposite offset would cancel out a major response of the previous offset. The whirling orbits before and after the offset couplers were also illustrated. The results, as expected, showed the in-phase offset displayed much larger radii than the anti-phase’s. The rotor’s orbits changed the whirling direction once the rotation fell within a certain range and this feature seemed to be unaffected by coupler offsets.


Author(s):  
Yan Litang

A substructure transfer matrix method for the dynamic analysis of multi-Rotor systems and complex composite systems is presented. When calculating, the rotor system should be decomposed into several single rotor shafts (substructures). Corresponding unknown external loads and deflections are applied to the separated surfaces, rigid support sections and ball joint sections respectively to replace the original connections. According to the connective and boundary conditions of the whole rotor system, a system of equations is established, from which the frequency equation results. The calculating formulas of vibration modes and of unbalanced response will be easily formed by linear combination method. All computations are performed with the transfer matrix method. This method is intelligible, readily programmed and much simpler than the current transfer matrix method and modal synthesis method.


Author(s):  
Qihan Li ◽  
Litang Yan ◽  
James F. Hamilton

This paper presents an analysis of the steady-state unbalance response of a dual-rotor gas turbine engine with a flexible intershaft squeeze film damper using a simplified transfer matrix method. The simplified transfer matrix method is convenient for the evaluation of the critical speed and response of the rotor system with various supports, shaft coupling, intershaft bearing, etc. The steady-state unbalance response of the rotor system is calculated for different shaft rotation speeds. The damping effects of an intershaft squeeze film damper with different radial clearances under various levels of rotor unbalance are investigated.


2006 ◽  
Vol 324-325 ◽  
pp. 1003-1006
Author(s):  
Ke Ming Wang ◽  
Song Xiang

Understanding dynamic behavior of a rotor system with a transverse crack is of great significance for operation reliability of rotating machinery. The transfer matrix method is widely used for rotor dynamic analysis, but it encounters difficulties modeling a crack. This study proposes a finite-width crack model that simulates the local stiffness reduction effect of a gaping crack in transfer matrix method. This model is obtained by comparing finite element analysis results of a shaft with a zero-width crack and its counterpart transfer matrix calculation results with a trial equivalent finite-width slot. Different shaft geometry and loading modes are considered to improve the generality of the model. An application example is given that uses the proposed model to calculate critical speeds of a multi-disk rotor system with a transverse crack at different positions.


Author(s):  
K. D. Gupta ◽  
K. Gupta ◽  
K. Athre

This paper presents a general formulation for the stability problem of a linear model of dual rotor system with intershaft bearing(s) employing an ‘extended’ transfer matrix method [9] using complex variables. The stability criterion employed is essentially an extension of leonhard’s stability criterion. An alternative concept of ‘margin of stability’ has been suggested. In contrast to other methods, the present formulation maintains the integrity of dual rotor system in totality, by considering exact junction conditions at intershaft bearing. And it is felt that it would prove to be an potential method for analyzing the stability of complex rotor systems.


1986 ◽  
Vol 108 (4) ◽  
pp. 605-612 ◽  
Author(s):  
Qihan Li ◽  
Litang Yan ◽  
J. F. Hamilton

This paper presents an analysis of the steady-state unbalance response of a dual-rotor gas turbine engine with a flexible intershaft squeeze film damper using a simplified transfer matrix method. The simplified transfer matrix method is convenient for the evaluation of the critical speed and response of the rotor system with various supports, shaft coupling, intershaft bearing, etc. The steady-state unbalance response of the rotor system is calculated for different shaft rotation speeds. The damping effects of an intershaft squeeze film damper with different radial clearances under various levels of rotor unbalance are investigated.


2013 ◽  
Vol 340 ◽  
pp. 69-74 ◽  
Author(s):  
Feng Jun Lv

Gear drive system is a complex rotor system through the gears, couplings and others connected. According to the vibration equation of the gear drive system, using the whole transfer matrix method, gear meshing force is analyzed and the whole transfer matrix of meshing gears is deduced. Numerical example shows that the whole transfer matrix method is applied to the vibration analysis of gear drive system has the advantages of convenient modeling, and accurate calculation.


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