نتایج جستجو برای: damped natural frequencies

تعداد نتایج: 576502  

2000
R. M. Jones R. H. Miller T. O. Raubenheimer G. V. Stupakov

The main linacs of the Next Linear Collider (NLC) will contain several thousand X-band RDDS (Rounded Damped Detuned Structures). The transverse wakefield in the structures is reduced by detuning the modal frequencies such that they destructively interfere and by four damping manifolds per structure which provide weak damping. Errors in the fabrication of the individual cells and in the alignmen...

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 ...

2001
G. Losurdo G. Calamai E. Cuoco L. Fabbroni G. Guidi M. Mazzoni R. Stanga F. Vetrano V. Dattilo F. Fidecaro F. Frasconi A. Gennai A. Giazotto I. Ferrante R. Passaquieti R. Poggiani R. Taddei A. Vicerè

interferometric gravitational wave detectors must be isolated from seismic noise. The VIRGO vibration isolator, called superattenuator, is fully effective at frequencies above 4 Hz. Nevertheless, the residual motion of the mirror at the mechanical resonant frequencies of the system are too large for the interferometer locking system and must be damped. A multidimensional feedback system, using ...

2004
Saleh Al-Takrouri Zoran Gajic

Order-reduction techniques based on system balancing are developed for linear discrete systems using the method of singular perturbations. The generalized residualization technique is introduced with three variants as improved tools for orderreduction at low and medium frequencies. The newly introduced techniques have the same theoretical upper error bound with respect to the H∞ norm of the red...

2001
G. Losurdo G. Calamai E. Cuoco L. Fabbroni G. Guidi M. Mazzoni R. Stanga F. Vetrano S. Mancini F. Paoletti A. Pasqualetti R. Passaquieti R. Poggiani R. Taddei A. Vicerè

interferometric gravitational wave detectors must be isolated from seismic noise. The VIRGO vibration isolator, called superattenuator, is fully effective at frequencies above 4 Hz. Nevertheless, the residual motion of the mirror at the mechanical resonant frequencies of the system are too large for the interferometer locking system and must be damped. A multidimensional feedback system, using ...

Journal: :Journal of neurophysiology 1988
L H Carney T C Yin

1. We recorded responses of low-frequency auditory nerve fibers (characteristic frequency (CF) less than 3 kHz) in the cat to resonant stimuli with varied natural frequencies, damping coefficients, and sound pressure levels. Responses to resonances were synchronized to frequencies lying between the peak frequency of the stimulus spectrum and a frequency near the fiber's CF. The frequency of the...

Journal: :Actuators 2023

This work is devoted to design, implement and validate an active mass damper (AMD) for vibration mitigation in slender structures. The control law, defined by means of genetic algorithm optimization, deployed on a low-cost processor (NI myRIO-1900), experimentally validated 13.5-m lively timber footbridge. As known, problems arising from human-induced vibrations slender, lightweight low-damped ...

Journal: :Industrial health 2010
Martin G R Toward Michael J Griffin

Models of the vertical apparent mass of the human body are mostly restricted to a sitting posture unsupported by a backrest and ignore the variations in apparent mass associated with changes in posture and changes in the magnitude of vibration. Using findings from experimental research, this study fitted a single degree-of-freedom lumped parameter model to the measured vertical apparent mass of...

2011
Umar Farooq

ABSTRACT This work presents the experimental evaluation of the state-variable modal decomposition (SVMD) method for modal parameter estimation of multi-degree-of-freedom and continuous vibration systems. Using output response ensembles only, the generalized eigenvalue problem is formed to estimate eigen frequencies and modal vectors for a lightly damped linear clamped-free thin experimental bea...

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