The influence of physical damping on the numerical stability of time integration analysis is an open question since decades ago. In this paper, it is shown that, under specific very general conditions, physical damping can be disregarded when studying the numerical stability. It is also shown that, provided the specific conditions are met, analysis of structural systems involved in extremely hi...

<p style='text-indent:20px;'>This paper examines the stabilization problem of axially moving Kirchhoff beam. Under nonlinear damping criterion established by slope-restricted condition, existence and uniqueness solutions closed-loop system equipped with time-delay disturbance at boundary is investigated via Faedo-Galerkin approximation method. Furthermore, solution continuously dependent ...

The Next Linear Collider (NLC) uses a damping ring for the electron beam, a pre-damping ring and a main damping ring for the positron beam to reduce the beam emittances. The requirements of the main damping ring kickers are to bend a 2 GeV beam by an angle of 2 mrad over a length of 1.2 m. This results in a required field of 139 G. The magnet aperture is 30×30 mm. The predamping ring kicker req...

in the current study the effect of casimir force and squeezed film damping on the pull-in instability and dynamic behavior of electrostatically actuated nano and micro electromechanical systems is investigated separately. linear elastic membrane theory is used to model the static and dynamic behavior of system for strip, annular and disk geometries. squeezed film damping effect is modeled using...

The problem of bunch lengthening in electron storage rings has been treated by many people, and there have been many experiments. In the typical experiment, the theory is used to determine the impedance of the ring. What has been lacking thus far, however, is a calculation of bunch lengthening that uses a carefully calculated ring impedance (or wakefield). In this paper we begin by finding the ...

Humans are able to adjust the accuracy of their movements to the demands posed by the task at hand. The variability in task execution caused by the inherent noisiness of the neuromuscular system can be tuned to task demands by both feedforward (e.g., impedance modulation) and feedback mechanisms. In this experiment, we studied both mechanisms, using mechanical perturbations to estimate stiffnes...

Turbo generator shafts are often subjected to cyclic torsion resulting in formation of large longitudinal cracks as well as circumferential cracks. The presence of these cracks could greatly impact the shaft resonance frequencies. In this paper, dynamic response of a shaft with longitudinal and circumferential cracks is investigated through a comprehensive analytical study. The longitudinally c...

In a previous paper (Hilton & Yi 1992), a systematic study was undertaken to determine how shapes of relaxation–time functions affect damping characteristics of isotropic viscoelastic materials. The significant parameters were the instantaneous and fully relaxed moduli (Regions A and E on Fig. 1), the two “knees” (B and D), the central slope (C) and anisotropic shift functions. The sensitivity ...

Two dimensional slope profile morphometric investigation in a part of the land failure prone Garhwal region of the Lesser Himalaya, Tehri district, U. P., India, indicates that the landslip morphology is closely related to the dominant movement processes active in this terrain. Technique developed for the morphometric analysis of landslips involves the use of five morphometric indices. Each ind...