ATTITUDE DRIFT OF TORQUE-FREE FLEXIBLE GYROS USING THE VISCOUS DAMPING MODEL

1988 ◽  
Vol 41 (4) ◽  
pp. 619-638
Author(s):  
H. G. CHESSER ◽  
F. P. J. RIMROTT
Keyword(s):  
Viscous Damping ◽  
Damping Model

'Geometric' Viscous Damping Model for Nearly Constant Beam Modal Damping

AIAA Journal ◽  
2013 ◽  
Vol 51 (7) ◽  
pp. 1688-1694 ◽  
Author(s):  
George A. Lesieutre ◽  
Jeffrey L. Kauffman
Keyword(s):  
Viscous Damping ◽  
Modal Damping ◽  
Damping Model

Effect of the elastic hysteresis term formulation and response to non-harmonic periodic excitations of a non-linear SDOF dynamical model with weak frequency-dependency in the time domain

2021 ◽  
pp. 095440622110182
Author(s):  
Christos Spitas ◽  
Mahmoud S Dwaikat ◽  
Vasileios Spitas
Keyword(s):  
Correction Factor ◽  
Time Domain ◽  
Hysteresis Loops ◽  
Domain Model ◽  
Viscous Damping ◽  
State Variables ◽  
Hysteretic Damping ◽  
Vibration Responses ◽  
The Time Domain ◽  
Damping Model

We elaborate a SDOF time-domain model for elastic hysteretic damping, by modifying the viscous damping model to introduce an instantaneous correction factor that recursively depends on the state variables of the system, such that the response exhibits weak dependency on frequency, corresponding to a large array of engineering materials. The effect of different formulations for calculating the instantaneous correction factor on the predicted hysteresis loops and the potential manifestation of singularities is studied. Hysteresis loops anticipated by the model are plotted and forced vibration responses to harmonic and other periodic non-harmonic excitations are simulated and discussed, also in comparison to the conventional viscous and Reid’s damping models.

Investigation of manipulator dynamics with a viscous damping model

2007 ◽  
Vol 221 (5) ◽  
pp. 513-517
Author(s):  
P Herman
Keyword(s):  
Degrees Of Freedom ◽  
Mass Matrix ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Viscous Damping ◽  
First Order ◽  
Manipulator Dynamics ◽  
Interesting Insight ◽  
Damping Model ◽  
Insight Into

In this article, some remarks concerning dynamics investigation of a manipulator described using first-order equations of motion with a viscous damping model is conducted. The viscous damping model arises from the Rayleigh dissipation potential and decomposition of the manipulator mass matrix. As a result, it takes into account both kinematic and mechanical parameters of the system. Moreover, the use of first-order equations of motion leads to obtaining some interesting insight into the manipulator dynamics. The proposed approach was tested on a three-degrees-of-freedom, three-dimensional Yasukawa-like robot.

scholarly journals Geometrically exact Cosserat rods with Kelvin–Voigt type viscous damping

2013 ◽  
Vol 4 (1) ◽  
pp. 79-96 ◽  
Author(s):  
J. Linn ◽  
H. Lang ◽  
A. Tuganov
Keyword(s):  
Elastic Moduli ◽  
Three Dimensional ◽  
Continuum Theory ◽  
Relaxation Processes ◽  
Viscous Damping ◽  
Strain Rates ◽  
Retardation Time ◽  
Cosserat Rods ◽  
Voigt Model ◽  
Damping Model

Abstract. We present the derivation of a simple viscous damping model of Kelvin–Voigt type for geometrically exact Cosserat rods from three-dimensional continuum theory. Assuming moderate curvature of the rod in its reference configuration, strains remaining small in its deformed configurations, strain rates that vary slowly compared to internal relaxation processes, and a homogeneous and isotropic material, we obtain explicit formulas for the damping parameters of the model in terms of the well known stiffness parameters of the rod and the retardation time constants defined as the ratios of bulk and shear viscosities to the respective elastic moduli. We briefly discuss the range of validity of the Kelvin–Voigt model and illustrate its behaviour for large bending deformations with a numerical example.

scholarly journals Numerical Investigation on Suppressing High Frequency Self-Excited Noises of Armature Assembly in a Torque Motor Using Ferrofluid

2017 ◽  
Vol 2017 ◽  
pp. 1-10
Author(s):  
Hasiaoqier Han ◽  
Songjing Li ◽  
Liang Guo ◽  
Qingwen Wu
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
High Frequency ◽  
Parallel Plate ◽  
Shear Thickening ◽  
Squeeze Flow ◽  
Resistance Force ◽  
Viscous Damping ◽  
The Mathematical Model ◽  
Damping Model

Attempting to suppress high frequency self-excited noises of armature assembly, ferrofluid is added to the working clearances of torque motor. The mathematical model of resistance force of ferrofluid applied to armature is derived theoretically from parallel plate squeeze flow theory and ferrofluid constitutive model in which shear thickening and shear thinning effects are taken into account. Then the equivalent physical model of ferrofluid is established according to the resistance force, and, through analysis, it can be further simplified as viscous damping model. Finally, the suppressing effect introduced by ferrofluid on high frequency noises of armature assembly is verified by comparing the results of numerical simulation with ferrofluid and that without ferrofluid.

Comparative Study of SDOF Response between Viscous Damping and Complex Damping Model

2011 ◽  
Vol 368-373 ◽  
pp. 938-941
Author(s):  
Rui Xue Chen ◽  
Ling Yun Peng ◽  
Wei Ming Yan
Keyword(s):  
Damping Ratio ◽  
Harmonic Excitation ◽  
Viscous Damping ◽  
Natural Period ◽  
Displacement Spectra ◽  
Earthquake Records ◽  
The Difference ◽  
Velocity Spectra ◽  
Damping Model ◽  
Complex Damping

This article summarizes the work regarding the complex and viscous damping models of SDOF system. Through calculating dynamic equations based on harmonic excitation, the result is that: when the excitation's period is less than the structure natural period, the displacement, velocity, acceleration responses of the complex damping system are stronger than the latter. Further, the displacement and the velocity spectra of some representative earthquake records are provided of two models, which show the similar trend as harmonic excitation. But the absolute acceleration spectra values of the complex damping model are higher than the other one at most time. And generally with the growing damping ratio and structure natural period, the difference is more significant. Under certain earthquake records, the structure displacement spectra values may differ by 17%, the velocity values differ by 20%, the acceleration values differ by 15%.

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