Nonlinear Dynamical Behaviors of a Cracked Turbocharger Rotor System with Base Excitation

2009 ◽  
Vol 10 (5) ◽  
Author(s):  
J.-P. Jing ◽  
J.-Z. Li ◽  
X.-Q. Liu ◽  
D.-S. Li ◽  
G. Meng
Keyword(s):  
Rotor System ◽  
Base Excitation ◽  
Nonlinear Dynamical ◽  
Dynamical Behaviors

Simulation and Experiment Analyses on Resonance for a Rotor System With Elastic Supports

2007 ◽  
Author(s):  
Qingkai Han ◽  
Li Wang ◽  
Hongliang Yao ◽  
Bangchun Wen
Keyword(s):  
Rotor System ◽  
Dynamical Equations ◽  
Interesting Phenomenon ◽  
Nonlinear Dynamical ◽  
Elastic Supports ◽  
Rotating Speed ◽  
Frequency Capture ◽  
Resonance Vibrations ◽  
Simulation And Experiment ◽  
Pass Through

There exist different vibration patterns when a rotor system runs up and down through its critical speed, in one of them, is the interesting phenomenon called frequency capture. Based on a specially designed rotor system which is supported by elastic supports, the resonance vibrations of frequency capture and pass-through are discussed both in time and frequency domains. The nonlinear dynamical equations are described in details for the system. The vibrations of capture, when the rotating speed is locked, are compared with normal pass-through by numerical simulations and experiments. Also the instantaneous displacement trajectories, 3D FFT waterfalls and phase space portraits are calculated and demonstrated for the above two resonance vibrations. In addition, the periodical motions are discussed for capture motions using both amplitude spectra and pseudo-Poincare mappings of simulation and experiment data.

Dynamic Mechanism of a Train Suspension System

2010 ◽  
Author(s):  
Albert C. J. Luo ◽  
Dennis O’Connor
Keyword(s):  
Numerical Simulations ◽  
System Parameter ◽  
Suspension System ◽  
Dynamic Mechanism ◽  
Impact Model ◽  
Periodic Motions ◽  
Chaotic Motions ◽  
Nonlinear Dynamical ◽  
Dynamical Behaviors ◽  
Mapping Structures

Nonlinear dynamical behaviors of a train suspension system with impacts are investigated. The suspension system is modelled through an impact model with possible stick between a bolster and two wedges. Based on the mapping structures, periodic motions of such a system are described. To understand the global dynamical behaviors of the train suspension system, system parameter maps are developed. Numerical simulations for periodic and chaotic motions are performed from the parameter maps.

Dynamic Response of the Vertical Rotor System to Base Excitation

2008 ◽  
Author(s):  
Jianli Zuo ◽  
Jianjun Wu ◽  
Ping Li ◽  
Shenjian Su
Keyword(s):  
Dynamic Response ◽  
Physical Model ◽  
High Speed ◽  
Lagrange Equation ◽  
Rotor System ◽  
Operating Speed ◽  
Base Excitation ◽  
Rotating Machine ◽  
Vertical Rotor ◽  
Rotary Speed

The physical model of a high-speed vertical rotating machine was taken as the example. The motion differential equations of the rotor system were established by the Lagrange equation and numerically solved by the Wilson-θ method. The whirling characteristics of the rotor excited by the base’s harmonic motions have been analyzed. The whirling directions are different between the rotor’s upper and lower ends. And the whirling characteristics of the rotor vary with the frequency of the base’s motion. Besides, there exists such a region of the rotor’s rotary speed, in which the whirling characteristics and amplitudes of the rotor system are relatively steady, so the aseismic tests at a certain lower speed can be done to examine the aseismic capability of the rotor system at operating speed.

ANALYSIS OF THE DYNAMIC BEHAVIOR OF A ROTOR SYSTEM UNDER BASE EXCITATION

2015 ◽  
Author(s):  
Marcelo Samora Sousa Jr ◽  
Aldemir Ap Cavalini Jr ◽  
Valder Steffen Jr
Keyword(s):  
Dynamic Behavior ◽  
Rotor System ◽  
Base Excitation

Study on the Hamilton Dynamical System of Wheel-and-Rail Dynamical Model of High-Speed Train

2015 ◽  
Vol 713-715 ◽  
pp. 99-102
Author(s):  
Hong Yun Shen ◽  
Jian Hua Du ◽  
Yu Lin Wang
Keyword(s):  
Dynamical System ◽  
Dry Friction ◽  
High Speed ◽  
Dynamical Model ◽  
High Speed Train ◽  
Damping Force ◽  
Nonlinear Dynamical ◽  
Dynamical Behaviors ◽  
Practical Engineering

The study on dynamical model of wheel and rail of high-speed train has attracted many researchers nowadays. According to the damping force and the dry friction between wheel and rail, the dynamical model of wheel and rail of high-speed train is constructed and the Hamilton dynamical system of this model is analyzed to discuss its nonlinear dynamical behaviors, which will benefit the practical engineering of high-speed train.

Dynamic Characteristic and Experiment Research of a Rotor-Bearing System Supported by Oil-Film

2010 ◽  
Vol 29-32 ◽  
pp. 1732-1737
Author(s):  
Chao Feng Li ◽  
Ji Shuang Dai ◽  
Xiao Peng Li ◽  
Bang Chun Wen
Keyword(s):  
Reduction Method ◽  
Three Dimensional ◽  
Experimental System ◽  
Rotor System ◽  
Practical Significance ◽  
Dimension Reduction Method ◽  
Experiment Research ◽  
Nonlinear Dynamical ◽  
Rotor Bearing ◽  
Fixed Interface

The FEM was employed to establish a nonlinear dynamical model of a rotor-bearing experimental system. The fixed interface mode synthesis dimension reduction method was adopted to to save the computing time.The Newmark-β method was employed to solve the reduced model numerically. And the three-dimensional spectrogram, bifurcation diagram, three-dimensional amplitude diagram, chart of axis trajectory, etc were used to analyze the nonlinear characteristic of the dynamic system comparing with those results of the experimental system. Results show that the numerical dynamic model can accurately reflect the characteristics of the nonlinear experimental system. So, it is very important practical significance to apply FEM and dimensional reduction theory into the research of the local nonlinear rotor system, which can provide more accurate verification and reference for the advanced nonlinear dynamic design of the complex rotor system.

DIFFUSION, INTERMITTENCY, AND NOISE-SUSTAINED METASTABLE CHAOS IN THE LORENZ EQUATIONS: EFFECTS OF NOISE ON MULTISTABILITY

2008 ◽  
Vol 18 (06) ◽  
pp. 1749-1758 ◽  
Author(s):  
WEN-WEN TUNG ◽  
JING HU ◽  
JIANBO GAO ◽  
VINCENT A. BILLOCK
Keyword(s):  
Fixed Point ◽  
Dynamical Systems ◽  
Nonlinear Dynamical Systems ◽  
Stable Fixed Point ◽  
Lorenz Equations ◽  
Periodic Forcing ◽  
Parameter Region ◽  
Interesting Phenomenon ◽  
Nonlinear Dynamical ◽  
Dynamical Behaviors

Multistability is an interesting phenomenon of nonlinear dynamical systems. To gain insights into the effects of noise on multistability, we consider the parameter region of the Lorenz equations that admits two stable fixed point attractors, two unstable periodic solutions, and a metastable chaotic "attractor". Depending on the values of the parameters, we observe and characterize three interesting dynamical behaviors: (i) noise induces oscillatory motions with a well-defined period, a phenomenon similar to stochastic resonance but without a weak periodic forcing; (ii) noise annihilates the two stable fixed point solutions, leaving the originally transient metastable chaos the only observable; and (iii) noise induces hopping between one of the fixed point solutions and the metastable chaos, a three-state intermittency phenomenon.

Dynamic Response of Nonlinear Oscillators With Hysteresis

2015 ◽  
Author(s):  
Biagio Carboni ◽  
Walter Lacarbonara
Keyword(s):  
Hysteresis Loops ◽  
Base Excitation ◽  
Response Curves ◽  
Restoring Force ◽  
Single Degree Of Freedom ◽  
Wire Ropes ◽  
Dynamical Behaviors ◽  
Nonlinear Features ◽  
Restoring Forces ◽  
Force Displacement

The nonlinear features of the steady-state periodic response of hysteretic oscillators are investigated. Frequency-response curves of base-excited single-degree-of-freedom (SDOF) systems possessing different hysteretic restoring forces are numerically obtained employing a continuation procedure based on the Jacobian of the Poincaré map. The memory-dependent restoring forces are expressed as a direct summation of linear and cubic elastic components and a hysteretic part described by a modified version of the Bouc-Wen law. The resulting force-displacement curves feature a pinching around the origin. Depending on the hysteresis material parameters (which regulate the shapes of the hysteresis loops), the oscillator exhibits hardening, softening and softening-hardening behaviors in which the switching from softening to hardening takes place above certain base excitation amplitudes. A comprehensive analysis in the parameters space is performed to identify the thresholds of these different behaviors. The restoring force features here considered have been experimentally obtained by means of an original rheological device comprising assemblies of steel and shape memory wire ropes. This study is carried out also with the aim of designing the restoring forces which give rise to dynamical behaviors useful for a variety of applications.

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