the ambient vibration measurement is a kind of output data-only dynamic testing where the traffics and winds are used as agents responsible for natural or environmental excitation. therefore an experimental modal analysis procedure for ambient vibration testing needs to base itself on output-only data. the modal analysis involving output-only measurements present a challenge that requires the u...

Vibration is a manual technique used widely to assist with the removal of pulmonary secretions. Little is known about how vibration is applied or its effect on the respiratory system. The purpose of this study was to describe mechanical consequences of vibration on the chest wall of a normal subject and the effects of vibration on expiratory flow rates and volumes. The effects of vibration were...

We report a demonstration of the measurement of the ratio between an optical modulation sideband component and the nonshifted light component by time-averaged heterodyne holography in off-axis and frequency-shifting configuration, through coherent frequency-division multiplexing with a dual optical local oscillator. Experimental results of sinusoidal vibration sensing are reported. This techniq...

in this study, the vibration behavior of functional graded (fg) circular and annular nanoplate embedded in a visco-pasternak foundation and coupled with temperature change is studied. the effect of in-plane pre-load and temperature change are investigated on the vibration frequencies of fg circular and annular nanoplate. to obtain the vibration frequencies of the fg circular and annular nanopla...

Real-world whole-body vibration exposures comprise motion in fore-aft, lateral, and vertical directions simultaneously. There can also be components of roll, pitch, and yaw. If evaluating vibration with respect to human response, most investigators will use methods defined in ISO 2631-1. This uses frequency weightings that were originally derived from laboratory studies of the subjective respon...

In this paper an algebraic technique for unbalance parameters identification along with an active control scheme for a rotor bearing system are presented. The system has two disks asymmetrically located along the shaft which is supported by a conventional ball bearing at one end and by an active suspension at the other one. The active suspension is based on linear springs and linear force actua...

We report on the use of a high-speed wavelength division multiplexing (WDM) technique for multiplexing Fiber Bragg Grating (FBG) sensors applied to structural Vibration Control for the measurement of strain, permitting many sensing devices along a single optical fiber at different locations collecting samples at 5000 Hz with microstrain resolution. In this demonstration, a cantilevered flexible...

Wiper is a device to wipe out dirt and raindrops from the windscreen. Hence, when a wiper system is operated, it has a potential to generate unwanted noise and vibration level. Reversal is one of the noise and vibration generated during the wiper operations. It is a medium frequency and self excited vibration that is often generated before and vice versa the direction. This leads to poor visibi...