scholarly journals Dynamic behavior of an AMB supported rotor subject to harmonic excitation

2008 ◽  
Vol 32 (7) ◽  
pp. 1370-1380 ◽  
Author(s):  
M.H. Eissa ◽  
U.H. Hegazy ◽  
Y.A. Amer
Keyword(s):  
Dynamic Behavior ◽  
Harmonic Excitation

Study on Dynamic Response of Visco-elastic Plate Under Transverse Periodic Load

2012 ◽  
Vol 13 (3-4) ◽  
Author(s):  
Xiaopeng Yan ◽  
Nianmei Zhang ◽  
Guitong Yang
Keyword(s):  
Dynamic Response ◽  
Dynamic Behavior ◽  
Thin Plate ◽  
Elastic Plate ◽  
Harmonic Excitation ◽  
Rectangular Thin Plate ◽  
Periodic Load ◽  
Compressive Loads

AbstractThe dynamic behavior of simple supported rectangular thin plate subjected to transverse harmonic excitation is investigated in this paper. The compressive loads

Nonlinear Modeling and Identification of the Dynamic Behavior of Polyurethane Foam

2001 ◽  
Author(s):  
R. Singh ◽  
P. Davies ◽  
A. K. Bajaj
Keyword(s):  
Dynamic Behavior ◽  
Polyurethane Foam ◽  
Nonlinear Modeling ◽  
Viscoelastic Model ◽  
Harmonic Excitation ◽  
Relaxation Kernel ◽  
Mass System ◽  
Response Data ◽  
State Response ◽  
Linear Viscoelastic

Abstract The analysis of the steady-state response of a polyurethane foam and mass system to harmonic excitation is given. The foam’s uni-directional dynamic behavior motion is modeled by using nonlinear stiffness, linear viscoelastic and velocity proportional damping components. The relaxation kernel for the viscoelastic model is assumed to be a sum of exponentials. Harmonic balance is used to develop one- and two-term solution approximations that are utilized for system identification. The identification process is based on least-squares minimization of a sub-optimal cost function that uses response data at various excitation frequencies and amplitudes. The effect of number, spacing and amplitudes of the harmonic input on the results of the model parameter estimation is discussed. Model-order choice and the feasibility of describing the system behavior at several input amplitudes with a single set of parameters are also addressed.

Investigation of the Dynamic Behavior of a Nonlinear Semi-Definite Mechanical System

2001 ◽  
Author(s):  
K. Alsaif
Keyword(s):  
Dynamic Response ◽  
Dynamic Behavior ◽  
Chaotic Behavior ◽  
Laser System ◽  
Resonance Region ◽  
Harmonic Excitation ◽  
Nonlinear Mechanical ◽  
Coulomb Type ◽  
Experimental Findings ◽  
Good Agreement

Abstract The study reported in this paper investigates the dynamic behavior of a semi-definite nonlinear mechanical structure. It consists of a cantilever beam with uniform thickness subjected to a harmonic excitation at the base; two hinged rigid plates are attached at its free end. The plates can execute oscillations in the horizontal plane without restoring moments. The friction at the hinges is modeled as a Coulomb type with a nonlinear friction coefficient. The excitation parameters at which chaotic motion of the hinged plates is initiated are investigated experimentally as well as numerically. It is shown that the prediction of the dynamic response of this semi-definite system is not accurate in the resonance region. The prediction fails due to the existence of chaotic behavior in that region. The measurement of the dynamic response of the system is conducted using a He-Ne laser system. The numerical results are found to be in a good agreement with the experimental findings.

Dynamic Behavior of a Harmonically Excited Electromechanical Drive With Elastic Couplings

1997 ◽  
Vol 119 (1) ◽  
pp. 21-30 ◽  
Author(s):  
V. Chaika ◽  
M. Mariunas
Keyword(s):  
Dynamic Behavior ◽  
Numerical Optimization ◽  
Vibration Analysis ◽  
Optimization Technique ◽  
Harmonic Excitation ◽  
Response Curves ◽  
Electromechanical Drive ◽  
Rotary Machines ◽  
Elastic Couplings ◽  
Parameter Values

Steady-state vibration of a lumped rotary system containing an electric drive is considered. The system is subjected to the harmonic excitation caused by the variation of voltage of the electric motor and the resisting torque of the operating machine. The influence of several types of elastic couplings on the dynamic behavior of an electromechanical drive is investigated. Numerical-analytical methods of nonlinear vibration analysis are applied. Frequency-response curves of rotary machines for different coupling cases are obtained. A numerical optimization technique for the estimation of the rational parameter values of the system is developed. Vibration controlling properties of standard and centrifugal couplings are compared.

Dynamic behavior of viscoelastic bodies during harmonic excitation

1980 ◽  
Vol 16 (7) ◽  
pp. 623-628 ◽  
Author(s):  
B. P. Gumenyuk ◽  
V. G. Karnaukhov
Keyword(s):  
Dynamic Behavior ◽  
Harmonic Excitation ◽  
Viscoelastic Bodies

scholarly journals Lyapunov Exponents of Early Stage Dynamics of Parametric Mutations of a Rigid Pendulum with Harmonic Excitation

2019 ◽  
Vol 24 (4) ◽  
pp. 90 ◽  
Author(s):  
Śmiechowicz ◽  
Loup ◽  
Olejnik
Keyword(s):  
Dynamic Behavior ◽  
Lyapunov Exponents ◽  
Dynamic Systems ◽  
Early Stage ◽  
Harmonic Excitation ◽  
System Response ◽  
Suspension Point ◽  
Chaotic Motions ◽  
Forced Responses ◽  
Similar Dynamic

This paper considers three dynamic systems composed of a mathematical pendulum suspended on a sliding body subjected to harmonic excitation. A comparative dynamic analysis of the studied parametric mutations of the rigid pendulum with inertial suspension point and damping was performed. The examined system with parametric mutations is solved numerically, where phase planes and Poincaré maps were used to observe the system response. Lyapunov exponents were computed in two ways to classify the dynamic behavior at relatively early stage of forced responses using two proven methods. The results show that with some parameters three systems exhibit a very similar dynamic behavior, i.e., quasi-periodic and even chaotic motions.

Ball bearing turbocharger vibration management: application on high speed balancer

2020 ◽  
Vol 21 (6) ◽  
pp. 619
Author(s):  
Kostandin Gjika ◽  
Antoine Costeux ◽  
Gerry LaRue ◽  
John Wilson
Keyword(s):  
Dynamic Behavior ◽  
High Speed ◽  
Internal Combustion Engines ◽  
Ball Bearing ◽  
Squeeze Film ◽  
Design And Technology ◽  
Squeeze Film Damper ◽  
Damping Coefficients ◽  
Bearing Loads ◽  
Stiffness And Damping

Today's modern internal combustion engines are increasingly focused on downsizing, high fuel efficiency and low emissions, which requires appropriate design and technology of turbocharger bearing systems. Automotive turbochargers operate faster and with strong engine excitation; vibration management is becoming a challenge and manufacturers are increasingly focusing on the design of low vibration and high-performance balancing technology. This paper discusses the synchronous vibration management of the ball bearing cartridge turbocharger on high-speed balancer and it is a continuation of papers [1–3]. In a first step, the synchronous rotordynamics behavior is identified. A prediction code is developed to calculate the static and dynamic performance of “ball bearing cartridge-squeeze film damper”. The dynamic behavior of balls is modeled by a spring with stiffness calculated from Tedric Harris formulas and the damping is considered null. The squeeze film damper model is derived from the Osborne Reynolds equation for incompressible and synchronous fluid loading; the stiffness and damping coefficients are calculated assuming that the bearing is infinitely short, and the oil film pressure is modeled as a cavitated π film model. The stiffness and damping coefficients are integrated on a rotordynamics code and the bearing loads are calculated by converging with the bearing eccentricity ratio. In a second step, a finite element structural dynamics model is built for the system “turbocharger housing-high speed balancer fixture” and validated by experimental frequency response functions. In the last step, the rotating dynamic bearing loads on the squeeze film damper are coupled with transfer functions and the vibration on the housings is predicted. The vibration response under single and multi-plane unbalances correlates very well with test data from turbocharger unbalance masters. The prediction model allows a thorough understanding of ball bearing turbocharger vibration on a high speed balancer, thus optimizing the dynamic behavior of the “turbocharger-high speed balancer” structural system for better rotordynamics performance identification and selection of the appropriate balancing process at the development stage of the turbocharger.

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