نتایج جستجو برای: viscous damping

تعداد نتایج: 41521  

2015

Abstract—Nowadays, energy dissipation devices are commonly used in structures. High rate of energy absorption during earthquakes is the benefit of using such devices, which results in damage reduction of structural elements, specifically columns. The hysteretic damping capacity of energy dissipation devices is the key point that it may adversely make analysis and design process complicated. Thi...

2002
Rakesh K. Goel

This paper presents results of an investigation on how supplemental viscous damping can be used to control excessive deformations in asymmetric-plan buildings. It is shown that symmetric distribution of supplemental damping devices in the building plan is not necessarily the best way to control excessive deformations in an asymmetric-plan building; a value of the damping eccentricity equal to t...

2010
Dorel Homentcovschi Bruce T. Murray Ronald N. Miles

The article presents an axi-symmetrical model for determining the total damping coefficient of a periodic perforated microelectromechanical systems (MEMS) microstructure for cases where the lubrication approximation yielding the Reynolds’ equation is no longer appropriate. Damping is modeled by solving for the viscous flow in an approximation of the periodic cell geometry using an equivalent ax...

1999
Erik A. Johnson Greg A. Baker Yozo Fujino

A BSTRACT : Stay cables, such as are used in cable-stayed bridges, are prone to vibration due to their low inherent damping characteristics. Transversely-attached passive viscous dampers have been implemented in many bridges to dampen such vibration. Several studies have investigated optimal passive linear viscous dampers; however, even the optimal passive device can only add a small amount of ...

2008
Sylvain Ervedoza Enrique Zuazua

We consider a class of viscous damped vibrating systems. We prove that, under the assumption that the damping term ensures the exponential decay for the corresponding inviscid system, then the exponential decay rate is uniform for the viscous one, regardless what the value of the viscosity parameter is. Our method is mainly based on a decoupling argument of low and high frequencies. Low frequen...

2010
Steven J. Cox Mark Embree

We consider the wave equation on a finite interval with fixed ends and nonuniform viscous damping. We prove that the spectrum of the associated damped wave operator uniquely determines an even damping. We then develop a refined asymptotic formula for the high frequencies. When the damping is even about the domain’s midpoint, terms in this expansion are Fourier coefficients for functions of the ...

Journal: :The Journal of the Acoustical Society of America 2007
Dorel Homentcovschi Ronald N Miles

The paper is a continuation of the works "Modelling of viscous damping of perforated planar micromechanical structures. Applications in acoustics" [Homentcovschi and Miles, J. Acoust. Soc. Am. 116, 2939-2947 (2004)] and "Viscous Damping of Perforated Planar Micromechanical Structures" [Homentcovschi and Miles, Sensors Actuators, A119, 544-552 (2005)] where design formulas for the case of an off...

Journal: :Sensors and actuators. A, Physical 2005
D Homentcovschi R N Miles

The paper gives an analytical approximation to the viscous damping coefficient due to the motion of a gas between a pair of closely spaced fluctuating plates in which one of the plates contains a regular system of circular holes. These types of structures are important parts of many microelectromechanical devices realized in MEMS technology as microphones, microaccelerometers, resonators, etc.T...

2007
L. Gualtieri J. A. Pons J. A. Miralles V. Ferrari

We derive the relativistic equations for stellar perturbations, including in a consistent way shear viscosity in the stress-energy tensor, and we numerically integrate our equations in the case of large viscosity. We consider the slow rotation approximation, and we neglect the coupling between polar and axial perturbations. In our approach, the frequency and damping time of the emitted gravitat...

1999
Greg A. Baker Erik A. Johnson Billie F. Spencer Yozo Fujino

Long cables, such as are used in cable-stayed bridges, are prone to vibration due to their low inherent damping characteristics. Several studies have investigated the use of an optimal viscous damper attached transversely to dampen such vibration. This paper investigates the potential for improved damping using a semiactive device. The equations of motion of the cable/damper system are reviewed...

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