Optimum Design of Rotor-Bearing Systems Considering the Nonlinear Effects of Bearing Fluid Forces

2005 ◽  
Author(s):  
Zhaobo Chen ◽  
Yinghou Jiao ◽  
Songbo Xia ◽  
Wenhu Huang
Keyword(s):  
Optimum Design ◽  
Fitness Function ◽  
Evolutionary Process ◽  
Nonlinear Effects ◽  
Radial Clearance ◽  
Chaotic Motions ◽  
Fluid Forces ◽  
Adaptive Procedures ◽  
Rotor Bearing ◽  
Bearing System

Genetic algorithms (GAs) are adaptive procedures that find solution to problems by an evolutionary process that mimics natural selection. In this paper, methods based on GAs have been developed and presented for design optimization of journal bearings in nonlinear rotor system. The GA uses a 30-bit chromosome to represent the bearing radial clearance, aspect ratio and lubricant viscosity, with 10-bit for each design variable. The instability onset speed of the system is taken as the fitness function in GA, in which the nonlinear effects of the bearing fluid forces are considered. The instability onset speed is defined in two different cases, that is, periodic and quasi-periodic or chaotic motions. To verify the effectiveness of the suggested method, a rigid rotor-bearing system is taken as an example to be optimized. The different crossover probabilities, mutation probabilities and population sizes are employed to analyze their influences on GA so that a set of appropriate parameters are chosen to be used in the final calculation. The results are compared with those obtained by numerical simulation. It is shown that the proposed algorithm is effective in the optimum design of rotor-bearing system.

Vibration Signature Analysis of a Rotor Bearing System Using Response Surface Method

2009 ◽  
Author(s):  
P. K. Kankar ◽  
Satish C. Sharma ◽  
S. P. Harsha
Keyword(s):  
Response Surface ◽  
Response Surface Method ◽  
High Speed ◽  
Vibration Response ◽  
Radial Clearance ◽  
System Response ◽  
Surface Waviness ◽  
Surface Method ◽  
Rotor Bearing ◽  
Bearing System

The vibration response of a rotor bearing system is extremely important in industries and is challenged by their highly non-linear and complex properties. This paper focuses on performance prediction using response surface method (RSM), which is essential to the design of high performance rotor bearing system. Response surface method is utilized to analysis the effects of design and operating parameters on the vibration response of a rotor-bearing system. A test rig of high speed rotor supported on rolling bearings is used. Vibration response of the healthy ball bearing and ball bearings with various faults are obtained and analyzed. Distributed defects are considered as surface waviness of the bearing components. Effects of internal radial clearance and surface waviness of the bearing components and their interaction are analyzed using design of experiment (DOE) and RSM.

Nonlinear effects of induced unbalance in the rod fastening rotor-bearing system considering nonlinear contact

2019 ◽  
Vol 90 (5) ◽  
pp. 917-943 ◽  
Author(s):  
Longkai Wang ◽  
Ailun Wang ◽  
Miao Jin ◽  
Qike Huang ◽  
Yijun Yin
Keyword(s):  
Nonlinear Effects ◽  
Nonlinear Contact ◽  
Rotor Bearing ◽  
Rod Fastening Rotor ◽  
Bearing System

Study on Bifurcation of Rigid Rotor Roller Bearings System Considering Nonlinear Dynamic Behavior

2010 ◽  
Vol 34-35 ◽  
pp. 467-471
Author(s):  
Li Cui ◽  
Jian Rong Zheng
Keyword(s):  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
Roller Bearing ◽  
Radial Clearance ◽  
Rigid Rotor ◽  
Rotating Speed ◽  
Rotor Bearing ◽  
Nonlinear Dynamic Behavior ◽  
Bifurcation And Stability ◽  
Bearing System

Rigid rotor roller bearing system displays complicated nonlinear dynamic behavior due to nonlinear Hertzian force of bearing. Nonlinear bearing forces of roller bearing and dynamic equations of rotor bearing system are established. The bifurcation and stability of the periodic motion of the system in radial clearance-rotating speed and ellipticity-rotating speed parametric domains are studied by use of continuation-shooting algorithm for periodic solutions of nonlinear non-autonomous dynamics system. Results show that the parameters of rotor bearing system should be designed carefully in order to obtain period-1 motion.

The bifurcation and chaos of a gear pair system based on a strongly non-linear rotor—bearing system

2010 ◽  
Vol 224 (9) ◽  
pp. 1891-1904 ◽  
Author(s):  
C-W Chang-Jian
Keyword(s):  
Operating Conditions ◽  
Speed Ratio ◽  
Gear Pair ◽  
Chaotic Motions ◽  
Systematic Analysis ◽  
Gear Mesh ◽  
Non Linear ◽  
Rotor Bearing ◽  
Linear Effects ◽  
Bearing System

A systematic analysis of the dynamic behaviours of a gear pair system based on a rotor—bearing system under strongly non-linear effects (i.e. non-linear suspension effect, non-linear oil-film force, non-linear rub-impact force, and non-linear gear mesh force) is presented in this study. The dynamic orbits of the system are observed using bifurcation diagrams plotted using the dimensionless unbalance coefficient, the dimensionless damping coefficient, and the dimensionless rotational speed ratio as control parameters. The onset of chaotic motion is specified from the phase diagrams, power spectra, Poincaré maps, Lyapunov exponents, and fractal dimension of the system. There exists various forms of periodic, quasi-periodic, and chaotic motions at different bifurcation parameters. The simulation results also found that highly non-periodic motions do exist in gear—rotor—bearing systems under those non-linear effects. The results presented in this study provide a better understanding of the operating conditions under which undesirable dynamic motion takes place in a gear—bearing system; they would therefore serve as a useful source of reference for engineers in designing and controlling such systems.

scholarly journals Optimum design of rotor-bearing system.

1984 ◽  
Vol 50 (460) ◽  
pp. 2338-2347
Author(s):  
Takuzo IWATUBO ◽  
Ryoji KAWAI
Keyword(s):  
Optimum Design ◽  
Rotor Bearing ◽  
Bearing System

Numerical Analysis of Nonlinear Behaviors of a Flexible Rotor Dynamic System with Turbulent Journal Bearings Support

2011 ◽  
Vol 142 ◽  
pp. 7-11
Author(s):  
Yan Jun Lu ◽  
Yong Fang Zhang ◽  
Xiao Yong Ma ◽  
Xu Liu
Keyword(s):  
Period Doubling ◽  
Journal Bearings ◽  
Flexible Rotor ◽  
Chaotic Motions ◽  
System A ◽  
Runge Kutta Method ◽  
Lubricant Flow ◽  
Rotor Bearing ◽  
The Rich ◽  
Bearing System

For description of rotor-bearing system, a symmetrical flexible rotor supported by two turbulent journal bearings is modeled. The analysis of the rotor-bearing system is implemented under the assumptions of turbulent lubricant flow and a long bearing approximation. The bifurcation and chaos behaviors of the system are investigated for various rotational speeds. The motion equations are solved by the self-adaptive Runge-Kutta method. The numerical results show that the bifurcation of nonlinear responses of the system varies with the rotational speed of the rotor. It is found that the rich and complex dynamic behaviors of the system include period-1, period-doubling, quasi-periodic and chaotic motions etc.

Analysis of dynamic behaviour of rotor-bearing system

2013 ◽  
Vol 228 (12) ◽  
pp. 2141-2161 ◽  
Author(s):  
Janko D Jovanović ◽  
Radoslav N Tomović
Keyword(s):  
Mathematical Model ◽  
Dynamic Behaviour ◽  
Direct Determination ◽  
Rolling Bearing ◽  
Plane Motion ◽  
Radial Clearance ◽  
Largest Lyapunov Exponent ◽  
Non Linear ◽  
Rotor Bearing ◽  
Bearing System

This paper deals with a non-linear mathematical model for simulation and analysis of a dynamic behaviour of a rotor-bearing system. The model is used for the simulation of plane motion of a centre of rotor’s cross-section which makes the model convenient for the analysis of vibrations generated in a rolling bearing as well as for the analysis of accuracy of the revolution of rotor supported on a rolling bearing. The model takes into account the following quantities: internal radial clearance, external radial load and unbalanced load. Differential equations of a motion are derived using Lagrange’s equations. The contacts between the balls and the rings are considered to be non-linear with a stiffness derived by the Hertzian theory of an elastic contact. The proposed model enables direct determination of local contact deformations which significantly reduces needed computations and CPU time. The results obtained by the model are used to reconstruct phase-space trajectories and Poincaré maps and to calculate the largest Lyapunov exponent in order to establish the stability of rotor-bearing system motion. A computer program is developed based on the mathematical model for the simulation and analysis of a dynamic behaviour of a rotor-bearing system.

Sign in / Sign up

Export Citation Format

Share Document