The Effects of Bearing Stiffness on Nonlinear Dynamic Behaviors of Multi-Mesh Gear Train

2012 ◽  
Author(s):  
T. N. Shiau ◽  
T. H. Young ◽  
J. R. Chang ◽  
K. H. Huang ◽  
C. R. Wang
Keyword(s):  
Chaotic Motion ◽  
Nonlinear Dynamic ◽  
Equations Of Motion ◽  
Nonlinear Dynamic Analysis ◽  
Gear Train ◽  
Time Varying ◽  
Kutta Method ◽  
Dynamic Behaviors ◽  
Runge Kutta Method ◽  
Bearing Stiffness

In this study, the nonlinear dynamic analysis of the multi-mesh gear train with elastic bearing effect is investigated. The gear system includes the three rigid shafts, two gear pairs and elastic bearings. The stiffness and damper coefficient of elastic bearing are considered. The equations of motion of nonlinear time-varying system are derived using Lagrangian approach. The Runge-Kutta Method is employed to determine the system dynamic behaviors including the bifurcation and chaotic motion. The results show that the periodic motion, quasi-periodical motion and chaos can be excited with the elastic bearing effect. Especially, the results also indicate the dynamic response will go from periodic to quasi-periodical before the chaotic motion when the bearing stiffness is increased.

Nonlinear Dynamic Analysis of a Multi-Gear Train With Time-Varying Mesh Stiffness Including Modification Coefficient Effect

2011 ◽  
Author(s):  
T. N. Shiau ◽  
J. R. Chang ◽  
K. H. Huang ◽  
C. J. Cheng ◽  
C. R. Wang
Keyword(s):  
Dynamic Analysis ◽  
Nonlinear Dynamic ◽  
Nonlinear Dynamic Analysis ◽  
Gear Train ◽  
Work Piece ◽  
Time Varying ◽  
Gear Pair ◽  
Mesh Stiffness ◽  
Harmonic Motion ◽  
Gear Profile

The nonlinear dynamic analysis of a multi-gear train with time-varying mesh stiffness on account of the modification coefficient effect is in vestigated in this paper. The proposed application of the modification coefficient will revise the center distance of the gear pair, avoid undercut and raise the mesh stiffness of the designed gear system. In this study, the gear profile is generated from the relationship between the rack cutter and the gear work piece by using the envelope theory. The rack cutter with the modification coefficient increases the mesh stiffness and thus enhances the strength of the gear tooth. Then the time-varying mesh stiffness at the contact position of the gear pair is calculated from the tooth deflection analysis using the generated gear profile. With the obtained time-varying mesh stiffness, the nonlinear dynamic behavior of multi-gear train is investigated by using Runge-Kutta integration method. The numerical results of the studied examples show the harmonic motion, sub-harmonic motion, chaotic motion and bifurcation phenomenon of the gear train.

Shaft Instabilities in Two-Stage Gear Systems

2013 ◽  
Vol 275-277 ◽  
pp. 930-935
Author(s):  
Zhe Rao ◽  
Chun Yan Zhou
Keyword(s):  
Multiple Scale ◽  
Gear System ◽  
Dynamic Equations ◽  
Time Varying ◽  
Kutta Method ◽  
Two Stage ◽  
Scale Method ◽  
System A ◽  
Runge Kutta Method ◽  
Intermediate Shaft

The present paper is focused on the torsional instabilities of the intermediate shaft in a two stage gear system. A theoretical model is established taking account in the torsional flexibility of the intermediate shaft and the meshing time-varying stiffness of the gears. Multiple scale method is applied to analysis the instability areas of the gear system for which the generalized modal coordinate is adopted. The result is certificated by numerical integrals of the dynamic equations by Runge-Kutta Method.

Accuracy and Reliability of Piecewise-Constant Method in Studying the Responses of Nonlinear Dynamic Systems

2015 ◽  
Vol 10 (2) ◽  
Author(s):  
Liming Dai ◽  
Xiaojie Wang ◽  
Changping Chen
Keyword(s):  
Numerical Methods ◽  
Dynamic Systems ◽  
Nonlinear Dynamic ◽  
Nonlinear Dynamical Systems ◽  
Nonlinear Dynamic Systems ◽  
Processing Unit ◽  
Kutta Method ◽  
Piecewise Constant ◽  
Runge Kutta Method ◽  
Runge Kutta

Accuracy and reliability of the numerical simulations for nonlinear dynamical systems are investigated with fourth-order Runge–Kutta method and a newly developed piecewise-constant (P-T) method. Nonlinear dynamic systems with external excitations are studied and compared with the two numerical approaches. Semianalytical solutions for the dynamic systems are developed by the P-T approach. With employment of a periodicity-ratio (PR) method, the regions of regular and irregular motions are determined and graphically presented corresponding to the system parameters, for the comparison of accuracy and reliability of the numerical methods considered. Central processing unit (CPU) time executed in the numerical calculations with the two numerical methods are quantitatively investigated and compared under the same computational conditions. Due to its inherent drawbacks, as found in the research, Runge–Kutta method may cause information missing and lead to incorrect conclusions in comparing with the P-T method.

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.

Computer Simulation of the Response of a Railway Vehicle Carbody

2002 ◽  
Author(s):  
M. Senthil Kumar ◽  
P. M. Jawahar
Keyword(s):  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Contact Forces ◽  
Railway Vehicle ◽  
Lateral Stiffness ◽  
Lateral Vibration ◽  
Kutta Method ◽  
Nonlinear Mathematical Model ◽  
Rail Vehicle ◽  
Runge Kutta Method

In this paper, a nonlinear mathematical model has been constructed by deriving the equations of motion of a Rail Vehicle carbody using Newton’s law. The nonlinear formula is used to evaluate the wheel rail contact forces. The nonlinear profile of wheel and rail are taken into account. Also the lateral stiffness of the track is taken into consideration. The equations of motion are derived for (a) Carbody with conventional wheelset (b) Carbody with unconventional wheelset (independently rotating wheels). For lateral vibration, 17 degrees of freedom are considered. The degrees of freedom represent lateral and yaw movements of 4 wheelsets and lateral, yaw and roll movements of the bogie and carbody. These equations of motion are transformed into a form suitable for numerical differential equation by Runge Kutta method. In the interest of computing economy, certain approximations have been introduced for calculating the creep forces. Sample results are given for a model of a typical railway vehicle used by the Indian Railways. The lateral dynamic response of the railway vehicle carbody for both conventional and unconventional wheelset has been analysed.

Dynamic analysis of open-loop mechanisms with multiple spatial revolute clearance joints

2018 ◽  
Vol 233 (2) ◽  
pp. 593-610 ◽  
Author(s):  
Lixin Yang ◽  
Xianmin Zhang ◽  
Yanjiang Huang
Keyword(s):  
Nonlinear Dynamic ◽  
Robot Manipulator ◽  
Equations Of Motion ◽  
Correction Method ◽  
Open Loop ◽  
Hertzian Contact ◽  
Dynamic Behaviors ◽  
Clearance Joints ◽  
Revolute Clearance Joint ◽  
Clearance Joint

Dynamic model of a typical open-loop mechanism with multiple spatial revolute clearance joints were established based on the Newton–Euler equations and the Hertzian contact deformation theory. An augmented constraint violation correction method was presented to solve the nonlinear dynamic equations of motion, which improved the global convergence and stability effectively. The nonlinear dynamic behaviors of a serial robot manipulator with two spatial revolute clearance joints were studied to demonstrate the effects of the location and coupling relationship of the clearance joints. Numerical results show that the influence of spatial revolute clearance joint on the dynamic behaviors of the open-loop mechanism is relatively stronger than that of the planar ones. The location of the spatial revolute clearance joints is an important factor to dynamic behavior of the system. The closer the spatial revolute clearance joint is to the end-effector, the stronger influence it has on the system. The spatial revolute clearance joints interact significantly with each another, which exhibits vigorous vibration with a higher frequency, larger amplitude, and deeper penetration. This work provides new insights into investigating the nonlinear dynamic behaviors of the systems with spatial revolute clearance joints.

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.

scholarly journals Dynamics and Control of a Tethered Satellite System Based on the SDRE Method

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Yong-Lin Kuo
Keyword(s):  
Nonlinear Dynamic ◽  
Equations Of Motion ◽  
Nonlinear Dynamic Analysis ◽  
Satellite System ◽  
Convergence Time ◽  
Tethered Satellite ◽  
Modeling And Control ◽  
Tethered Satellite System ◽  
Dynamics And Control ◽  
And Control

This paper presents the nonlinear dynamic modeling and control of a tethered satellite system (TSS), and the control strategy is based on the state-dependent Riccati equation (SDRE). The TSS is modeled by a two-piece dumbbell model, which leads to a set of five nonlinear coupled ordinary differential equations. Two sets of equations of motion are proposed, which are based on the first satellite and the mass center of the TSS. There are two reasons to formulate the two sets of equations. One is to facilitate their mutual comparison due to the complex formulations. The other is to provide them for different application situations. Based on the proposed models, the nonlinear dynamic analysis is performed by numerical simulations. Besides, to reduce the convergence time of the librations of the TSS, the SDRE control with a prescribed degree of stability is developed, and the illustrative examples validate the proposed approach.

Vibration of a Crane System Superimposed upon its Nominal Motion

2012 ◽  
Vol 430-432 ◽  
pp. 1847-1850
Author(s):  
Jin Fu Zhang ◽  
Qi Ren Luo
Keyword(s):  
Fourth Order ◽  
Equations Of Motion ◽  
Kutta Method ◽  
Runge Kutta Method ◽  
Actual Motion ◽  
Runge Kutta ◽  
The Relationship

The equations of motion for a crane system with considering the elasticity of the hoisting cable are derived. Using such equations and the relationship between the actual motion and the nominal motion of the crane system, the equations of vibration of the crane system superimposed upon its nominal motion are established. The responses of the vibration can be determined by numerically integrating the equations using the fourth order Runge–Kutta method. Based on the analysis of responses of the vibration, some conclusions concerning the vibration are obtained.

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