We report a self-powered, lightweight and cost-effective active sensor system for vibration monitoring with multiplexed operation based on contact electrification between sensor and detected objects. The as-fabricated sensor matrix is capable of monitoring and mapping the vibration state of large amounts of units. The monitoring contents include: on-off state, vibration frequency and vibration ...

An analytical solution for nonlinear vibration of an initially stressed beam with elastic end restraints resting on a nonlinear elastic foundation is obtained. As a first step in solving nonlinear vibration equation, the linear vibration mode functions for a beam with elastic end restraints resting on a linear elastic foundation are obtained. Then, the nonlinear vibration equation is solved by ...

Steam-induced vibration is a kind of self-excited vibration which is one of the most important issues affecting the operation reliability of steam turbines. A lot of actual cases of steam-induced vibration of steam turbine were collected in this work. And steam-induced vibration fault was statistical and classified by fault reason, happened time, occurrence load and fault severity. The statisti...

In this paper, natural frequency and response of forced vibration of composite laminated conical shells under different boundary conditions are investigated. To this end, equations of Donnell's thin shell theory are used as governing equations. The analytical Galerkin method together with beam mode shapes as weighting functions is employed to solve the problem. Due to importance of boundary con...

Energy balance method is an effective and simple method which is used in the amplitude calculation of Aeolian vibration in transmission lines with Stockbridge damper. However, the accuracy of the results obtained by this method, heavily depends on the assumed mode shapes of the conductor vibration. In this study, by considering an appropriate model for the conductor vibration, a comprehensive m...

This paper presents the adaptive control scheme with sliding mode compensator for vibration control problem in the presence of disturbance. The dynamic model of the flexible cantilever beam using finite element modeling is derived. The adaptive control with sliding mode compensator using output feedback for output tracking is developed to reject the external disturbance, and to improve the trac...

In this paper, a discrete-time frequency-shaped sliding mode control (FSSMC) is proposed for audio-vibration rejection in Hard Disk Drives (HDDs). Such vibrations cause significant degradation of the servo performance and have become a major concern in the HDD industry. The proposed FSSMC involves the frequency-shaped sliding surface design based on peak filters, aiming to provide frequency dep...

the purpose of this study was to assess exposure to hand-arm vibration in tiller users, forty users of tiller in northeastern provinces of iran were examined to measure hand-arm vibration parameters such as root mean square acceleration (rms), total equivalent acceleration, vibration dose value (vdv) and crest factor in three directions (x, y, and z) and various operating modes for comparing th...

An accurate autoregressive (AR) model can reflect the characteristics of a dynamic system based on which the fault feature of gear vibration signal can be extracted without constructing mathematical model and studying the fault mechanism of gear vibration system, which are experienced by the time-frequency analysis methods. However, AR model can only be applied to stationary signals, while the ...

The vibration of the organ of Corti, a three-dimensional micromechanical structure that incorporates the sensory cells of the hearing organ, was measured in three mutually orthogonal directions. This was achieved by coupling the light of a laser Doppler vibrometer into the side arm of an epifluorescence microscope to measure velocity along the optical axis of the microscope, called the transver...