Dynamic Analysis of Complex Composite Rotor Systems With Substructure Transfer Matrix Method

1985 ◽  
Author(s):  
Yan Litang
Keyword(s):  
Dynamic Analysis ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Synthesis Method ◽  
Frequency Equation ◽  
Rotor System ◽  
Combination Method ◽  
Rotor Systems ◽  
Modal Synthesis

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.

A Finite-Width Crack Model for Rotor Dynamic Analysis by Transfer Matrix Method

2006 ◽  
Vol 324-325 ◽  
pp. 1003-1006
Author(s):  
Ke Ming Wang ◽  
Song Xiang
Keyword(s):  
Dynamic Analysis ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Transverse Crack ◽  
Rotor System ◽  
Crack Model ◽  
Finite Width ◽  
Stiffness Reduction ◽  
Rotor Dynamic

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.

Stability Analysis of Dual Rotor System by Extended Transfer Matrix Method

1989 ◽  
Author(s):  
K. D. Gupta ◽  
K. Gupta ◽  
K. Athre
Keyword(s):  
Transfer Matrix ◽  
Stability Criterion ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Potential Method ◽  
Rotor System ◽  
Junction Conditions ◽  
Rotor Systems ◽  
Margin Of Stability ◽  
The Stability

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.

A Transfer Matrix Technique for Evaluating the Natural Frequencies and Critical Speeds of a Rotor With Multiple Flexible Disks

1992 ◽  
Vol 114 (2) ◽  
pp. 242-248 ◽  
Author(s):  
F. Wu ◽  
G. T. Flowers
Keyword(s):  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Natural Frequencies ◽  
Research Effort ◽  
Dynamical Behavior ◽  
Rotor System ◽  
Matrix Formulation ◽  
Critical Speeds ◽  
Rotor Systems

The influence of disk flexibility on the rotordynamical behavior of turbomachinery is a topic that is of some concern to designers and analysts of such equipment. Research in this area has indicated that disk flexibility may significantly alter the dynamical behavior of a rotor system. This research effort is concerned with developing a procedure to account for disk flexibility which can readily be used for investigating how such effects might influence the natural frequencies and critical speeds of practical rotor systems. A transfer matrix procedure is developed in this work in which the disk flexibility effects are accounted for by means of additional terms included in the transfer matrix formulation. In this way the efficiency and practicality of the transfer matrix method is retained. To demonstrate this technique, a simple rotor system is studied for the effect of disk flexibility and the results discussed.

Dynamic Analysis of Geared Rotor-Bearing Systems by the Transfer Matrix Method

1995 ◽  
Author(s):  
Siu-Tong Choi ◽  
Sheng-Yang Mau
Keyword(s):  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Vibration Analysis ◽  
Transmission Error ◽  
Mode Shapes ◽  
Rotor Systems ◽  
Gear Mesh ◽  
Mass Unbalance ◽  
Rotor Bearing

Abstract In this paper, an analytical study of the dynamic characteristics of geared rotor-bearing systems by the transfer matrix method is presented. Rotating shafts are modeled as Timoshenko beam with shear deformation and gyroscopic effects taken into account. The gear mesh is modeled as a pair of rigid disks connected by a spring-damper set and a transmission-error exciter. The transfer matrix of a gear mesh is developed. The coupling motions of the lateral and torsional vibration are studied. In free vibration analysis of geared rotor systems, natural frequencies and corresponding mode shapes, and the whirl frequencies under different spin speeds are determined. Effects of bearing stiffness, isotropic and orthotropic bearings, pressure angle of the gear mesh are studied. In steady-state vibration analysis, responses due to the excitation of mass unbalance and the transmission error are studied. Parametric characteristics of geared rotor systems are discussed.

Dynamic characteristics of coupling shaft system in tufting machine based on the Riccati whole transfer matrix method

2016 ◽  
Vol 231 (2) ◽  
pp. 356-371 ◽  
Author(s):  
Shuang Huang ◽  
Xinfu Chi ◽  
Yang Xu ◽  
Yize Sun
Keyword(s):  
Transfer Matrix ◽  
Dynamic Characteristics ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Complex Dynamic ◽  
Rotor Systems ◽  
Machine Type ◽  
Shaft System

Focusing on tufting machine type DHUN801D-400, the complex dynamic model of coupling shaft system is built by using Riccati whole transfer matrix method, and the natural frequencies and mode shapes are analyzed. First, the components of coupling shafts system in tufting machine are introduced. Second, the structures of coupling shafts system are discretized and simplified. Third, the transfer matrix is constructed, the model is solved by using Riccati whole transfer matrix method, and then natural frequencies and mode shapes are obtained. Finally, the experimental results are quoted to demonstrate the applicability of the model. The results indicate that the Riccati whole transfer matrix method is well applicable for modeling the dynamics of complex multi-rotor systems.

Vibration Analysis of Multi-Disk Multi-Profiled Shaft-Rotor Systems

2014 ◽  
Vol 612 ◽  
pp. 17-22 ◽  
Author(s):  
P.M.G. Bashir Asdaque ◽  
R.K. Behera ◽  
Jakeer Hussain Shaik
Keyword(s):  
Dynamic Characteristics ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Vibration Analysis ◽  
Shear Force ◽  
Bending Moment ◽  
Rotor System ◽  
Step Response ◽  
Rotor Systems

Cantilevered shaft-rotor systems consisting of multi disks and multi profiled shafts are considered. In this paper the procedures for the determination of the deflection, slope, shear force and bending moment at the extremities of the shaft are employed. Critical speeds or whirling frequency conditions are computed using transfer matrix method (TMM). For particular shaft-lengths, rotating speeds and shaft-profiles, the response of the system is determined for the establishment of the dynamic characteristics. A built-in shaft-rotor system consisting of two disks and two different profiled shafts is investigated for illustration purposes. Step response of the multi profiled shaft-rotor system is also found out.

VIBRATIONS OF A ROTOR SYSTEM WITH MULTIPLE COUPLER OFFSETS

2011 ◽  
Vol 35 (1) ◽  
pp. 81-100
Author(s):  
Chao-Yang Tsai ◽  
Shyh-Chin Huang
Keyword(s):  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Rotational Speed ◽  
Matrix Method ◽  
Rotor System ◽  
Response Amplitude ◽  
External Excitation ◽  
Phase Offset ◽  
Major Response ◽  
Before And After

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.

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