scholarly journals Nonlinear Dynamic Analysis of Rotor-Bearing System with Cubic Nonlinearity

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Guofang Nan ◽  
Yujie Zhu ◽  
Yang Zhang ◽  
Wei Guo
Keyword(s):  
Nonlinear Dynamic ◽  
Nonlinear Dynamic Analysis ◽  
Hertzian Contact ◽  
Stable Operation ◽  
Nonlinear Stiffness ◽  
Cubic Nonlinearity ◽  
Dynamic Behaviors ◽  
Mass Eccentricity ◽  
Rotor Bearing ◽  
Bearing System

Nonlinear dynamic characteristics of a rotor-bearing system with cubic nonlinearity are investigated. The comprehensive effects of the unbalanced excitation, the internal clearance, the nonlinear Hertzian contact force, the varying compliance vibration, and the nonlinear stiffness of support material are considered. The expression with the linear and the cubic nonlinear terms is adopted to characterize the synthetical nonlinearity of the rotor-bearing system. The effects of nonlinear stiffness, rotating speed, and mass eccentricity on the dynamic behaviors of the system are studied using the rotor trajectory diagrams, bifurcation diagrams, and Poincaré map. The complicated dynamic behaviors and types of routes to chaos are found, including the periodic doubling bifurcation, sudden transition, and quasiperiodic from periodic motion to chaos. The research results show that the system has complex nonlinear dynamic behaviors such as multiple period, paroxysmal bifurcation, inverse bifurcation, jumping phenomena, and chaos; the nonlinear characteristics of the system are significantly enhanced with the increase of the nonlinear stiffness, and the material with lower nonlinear stiffness is more conducive to the stable operation of the system. The research will contribute to a comprehensive understanding of the nonlinear dynamics of the rotor-bearing system.

Nonlinear dynamic analysis of cutting head-rotor-bearing system of the roadheader

2019 ◽  
Vol 33 (3) ◽  
pp. 1033-1043
Author(s):  
Zhilong Huang ◽  
Zhongchao Zhang ◽  
Yiming Li ◽  
Guiqiu Song ◽  
Yang He
Keyword(s):  
Dynamic Analysis ◽  
Nonlinear Dynamic ◽  
Nonlinear Dynamic Analysis ◽  
Cutting Head ◽  
Rotor Bearing ◽  
Bearing System

Nonlinear dynamic analysis of a rotor-bearing system with porous tilting pad bearing support

2018 ◽  
Vol 94 (2) ◽  
pp. 1391-1408 ◽  
Author(s):  
Yihua Wu ◽  
Kai Feng ◽  
Yun Zhang ◽  
Wanhui Liu ◽  
Wenjun Li
Keyword(s):  
Dynamic Analysis ◽  
Nonlinear Dynamic ◽  
Nonlinear Dynamic Analysis ◽  
Tilting Pad ◽  
Rotor Bearing ◽  
Bearing System

Chaos and Nonlinear Dynamic Analysis of Porous Air Bearing System

2015 ◽  
Vol 764-765 ◽  
pp. 204-207
Author(s):  
Cheng Chi Wang ◽  
Jui Pin Hung
Keyword(s):  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
Effective Means ◽  
Nonlinear Dynamic Analysis ◽  
Transformation Method ◽  
Dynamic Responses ◽  
Air Bearing ◽  
Dynamic Behaviors ◽  
Rotor Mass ◽  
Bearing System

The chaos and nonlinear dynamic behaviors of porous air bearing system are studied by a hybrid numerical method combining the finite difference method (FDM) and differential transformation method (DTM). The numerical results are verified by two different schemes including hybrid method and FDM and the current analytical results are found to be in good agreement. Furthermore, the results reveal the changes which take place in the dynamic behavior of the bearing system as the rotor mass is increased. From the dynamic responses of the rotor center, they reveal complex dynamic behaviors including periodic, sub-harmonic motion and chaos. The results of this study provide an understanding of the nonlinear dynamic behavior of PAB systems characterized by different rotor masses. Specifically, the results have shown that system exists chaotic motion over the ranges of rotor mass 10.66≤Mr<13.7kg. The proposed method and results provide an effective means of gaining insights into the porous air bearing systems.

Nonlinear dynamic characteristics of a three-dimensional rod-fastening rotor bearing system

2014 ◽  
Vol 229 (5) ◽  
pp. 882-894 ◽  
Author(s):  
Yi Liu ◽  
Heng Liu ◽  
Xin Wang ◽  
Minqing Jing
Keyword(s):  
Dynamic Characteristics ◽  
Nonlinear Dynamic ◽  
Three Dimensional ◽  
Dynamic Features ◽  
Stability Margins ◽  
Mass Eccentricity ◽  
Nonlinear Dynamic Characteristics ◽  
Rotor Bearing ◽  
Rod Fastening Rotor ◽  
Bearing System

The nonlinear dynamic characteristics of three-dimensional rod-fastening rotor bearing system are investigated in this paper. The rod-fastening rotor includes discontinuous shaft, rotating disks, circumferentially distributed rods, and macrointerfaces between disks. The first three parts are discretized by three dimensional elements, and the macrointerfaces are connected by some springs whose stiffness is determined by a proposed linear partition method. For comparison, the three-dimensional dynamic model of a corresponding complete rotor bearing system is also built. After the rod-fastening and complete rotor bearing system are reduced by a component mode synthesis, periodic motions and stability margins are calculated by using the shooting method and path-following technique, and the local stability of system is obtained by using the Floquet theory. Comparative results show the both systems have a resemblance in the bifurcation features when mass eccentricity and rotating speed are changed. The vibration response has the identical frequency components when typical bifurcations occur. The dynamic stress is obtained by regarding the displacements of all nodes as load. Moreover, the unbalanced and insufficient of the pre-tightening forces lead to obvious disadvantageous influence on the stability and vibration of the both systems. Generally, this paper considers the interfacial effect of the rod-fastening rotor bearing system and the relative nonlinear dynamic features are obtained.

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