scholarly journals Analysis of parameters effects on crack breathing and propagation in shaft of rotor dynamic systems

2013 ◽  
Vol 16 (4) ◽  
pp. 867-873 ◽  
Author(s):  
M. Serier ◽  
A. Lousdad ◽  
K. Refassi ◽  
A. Megueni
Keyword(s):  
Dynamic Systems ◽  
Rotor Dynamic

Periodic Solutions in Rotor Dynamic Systems With Nonlinear Supports: A General Approach

1989 ◽  
Vol 111 (2) ◽  
pp. 187-193 ◽  
Author(s):  
C. Nataraj ◽  
H. D. Nelson
Keyword(s):  
Dynamic Systems ◽  
Original Problem ◽  
Squeeze Film ◽  
Algebraic Equations ◽  
Trigonometric Collocation ◽  
Nonlinear Algebraic Equations ◽  
The Stability ◽  
Future Work ◽  
Rotor Dynamic ◽  
Large Rotor

A new quantitative method of estimating steady state periodic behavior in nonlinear systems, based on the trigonometric collocation method, is outlined. A procedure is developed to analyze large rotor dynamic systems with nonlinear supports by the use of the above method in conjunction with Component Mode Synthesis. The algorithm discussed is seen to reduce the original problem to solving nonlinear algebraic equations in terms of only the coordinates associated with the nonlinear supports and is a big improvement over commonly used integration methods. The feasibility and advantages of the procedure so developed are illustrated with the help of an example of a typical rotor dynamic system with an uncentered squeeze film damper. Future work on the investigation of the stability of the periodic response so obtained is outlined.

Prediction of Periodic Response of Rotor Dynamic Systems With Nonlinear Supports

1995 ◽  
Author(s):  
Yu Wang
Keyword(s):  
Dynamic Systems ◽  
Nonlinear Differential Equations ◽  
Squeeze Film ◽  
Element Formulation ◽  
Algebraic Equations ◽  
Periodic Response ◽  
Nonlinear Algebraic Equations ◽  
Nodal Displacements ◽  
The Time Domain ◽  
Rotor Dynamic

Abstract A numerical-analytical method for estimating steady-state periodic behavior of nonlinear rotordynamic systems is presented. Based on a finite element formulation in the time domain, this method transforms the nonlinear differential equations governing the motion of large rotor dynamic systems with nonlinear supports into a set of nonlinear algebraic equations with unknown temporal nodal displacements. A procedure is proposed to reduce the resulting problem to solving nonlinear algebraic equations in terms of the coordinates associated with the nonlinear supports only. The result is a simple and efficient approach for predicting all possible fundamental and sub-harmonic responses. Stability of the periodic response is readily determined by a direct use of Floquet’s theory. The feasibility and advantages of the proposed method are illustrated with two examples of rotor-bearing systems of deadband supports and squeeze film dampers, respectively.

scholarly journals Eigensolution Reanalysis of Rotor Dynamic Systems by the Generalized Receptance Method

1982 ◽  
Author(s):  
A. B. Palazzolo ◽  
Bo Ping Wang ◽  
W. D. Pilkey
Keyword(s):  
Optimal Design ◽  
Dynamic Systems ◽  
Natural Frequencies ◽  
Rotor Systems ◽  
Receptance Method ◽  
Rotor Bearings ◽  
Rotor Dynamic

A method is presented for efficiently calculating the damped natural frequencies of complex rotor bearings systems. The procedure is applicable to the repeated reanalysis of rotor systems during the search for an optimal design. The generalized receptances used in the method are calculated with a series of formulas that improves the convergence characteristics when only an incomplete set of modes is available. A nonsynchronous gyroscopic rotor example is examined to illustrate the reanalysis procedure.

scholarly journals Using the Modal Method in Rotor Dynamic Systems

2003 ◽  
Vol 9 (3) ◽  
pp. 181-196
Author(s):  
Eduard Malenovský
Keyword(s):  
Finite Element Method ◽  
Collocation Method ◽  
Dynamic Systems ◽  
Theoretical Basis ◽  
The Finite Element Method ◽  
Transient Responses ◽  
Technical Application ◽  
Trigonometric Collocation ◽  
Rotor Dynamic ◽  
Modal Method

This article deals with computational modeling of nonlinear rotor dynamic systems. The theoretical basis of the method of dynamic compliances and the modal method, supplemented by the method of trigonometric collocation, are presented. The main analysis is focused on the solutions of the eigenvalue problem and steady-state and transient responses. The algorithms for solving this range of problems are presented. The finite element method, the method of dynamic compliances, and the modal method are supplemented by the trigonometric collocation method. The theoretical analysis is supplemented by the solution of a model task, which is focused on the application of the trigonometric collocation method. The solution of a technical application, which is a pump, is presented in this article.

Prediction of Periodic Response of Rotor Dynamic Systems With Nonlinear Supports

1997 ◽  
Vol 119 (3) ◽  
pp. 346-353 ◽  
Author(s):  
Yu Wang
Keyword(s):  
Dynamic Systems ◽  
Nonlinear Differential Equations ◽  
Squeeze Film ◽  
Element Formulation ◽  
Algebraic Equations ◽  
Periodic Response ◽  
Nonlinear Algebraic Equations ◽  
Nodal Displacements ◽  
The Time Domain ◽  
Rotor Dynamic

A numerical-analytical method for estimating steady-state periodic behavior of nonlinear rotordynamic systems is presented. Based on a finite element formulation in the time domain, this method transforms the nonlinear differential equations governing the motion of large rotor dynamic systems with nonlinear supports into a set of nonlinear algebraic equations with unknown temporal nodal displacements. A procedure is proposed to reduce the resulting problem to solving nonlinear algebraic equations in terms of the coordinates associated with the nonlinear supports only. The result is a simple and efficient approach for predicting all possible fundamental and sub-harmonic responses. Stability of the periodic response is readily determined by a direct use of Floquet’s theory. The feasibility and advantages of the proposed method are illustrated with two examples of rotor-bearing systems of deadband supports and squeeze film dampers, respectively.

Using the Modal and Trigonometric Collocation Methods in Rotor Dynamic Systems

2004 ◽  
Vol 126 (2) ◽  
pp. 229-234 ◽  
Author(s):  
Eduard Malenovsky´
Keyword(s):  
Dynamic Systems ◽  
Theoretical Basis ◽  
Collocation Methods ◽  
The Finite Element Method ◽  
Trigonometric Collocation ◽  
Steady State Responses ◽  
State Responses ◽  
Rotor Dynamic ◽  
Modal Method ◽  
Transient And Steady State

This article deals with the computational modeling of nonlinear rotor dynamic systems. The theoretical basis of the modal method, and combination with the method of dynamic compliances supplemented by the method of trigonometric collocation, is presented. The main analysis is focused on the solutions of transient and steady state responses. The algorithms for solving this range of problems are presented. The finite element method is the basis for both methods. The theoretical analysis is supplemented with a solution of an example model.

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