This paper presents analytical models, as well as numerical and experimental verification of intrinsic dissipation due to thermoelastic loss in tuning-fork resonator. The thermoelastic analytical governing equations are created for resonator vibrating at drive-mode and sense-mode, and thermoelastic vibration field quantities are deduced. Moreover, the theoretical values are verified that coinci...

Multi-frequency scanning near-field optical microscopy, based on a quartz tuning fork-probe (QTF-p) sensor using the first two orders of in-plane bending symmetrical vibration modes, has recently been developed. This method can simultaneously achieve positional feedback (based on the 1st in-plane mode called the low mode) and detect near-field optically induced forces (based on the 2nd in-plane...

Electronic speckle pattern interferometry (ESPI) was used for tuning and visualization of natural frequencies of a square laminate plate with rounded corners and chamfers. The plate was excited to resonant vibration by a sinusoidal acoustical source, which provided a continuous range of audio frequencies. Numerical calculations of resonant frequencies and mode shapes based on a finite element p...

Suppression of Random Vibration in Flexible Structures using a Hybrid Vibration Absorber M.H. Tso, J. Yuan, W.O. Wong Abstract A design method is proposed to suppress stationary random vibration in flexible structures using a hybrid vibration absorber (HVA). While the traditional vibration absorber can damp down the vibration mainly at the pre-tuned mode of the primary structure, active damping...

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...

This paper represents the first effort in seismic fragility analysis of a structure using a structural analysis model developed on the basis of measured vibration data. An instrumented highway bridge is used to demonstrate the analysis procedure involving measuring ambient vibration, identifying modal parameters from the measured data, updating a preliminary FE model (obtained from structural d...

This paper introduces the working principle of the two-stage decoupled micro-machined gyroscope, and establishes the vibration equation of the driving mode. By solving the differential equation, the analytical solution and the amplitude-frequency characteristics of the driving mode are obtained. By the visual measurement based on high-speed photography and the post image processing, it measures...

Abstract Inthispaper,anewsemi-activemagnetorheological(MR)enginemountinhalfcarmodelisproposed for improving ride comfort. Such a model uses a dynamic sliding mode controller. It operates as a controller system for controlling the magnetic field strength of the engine mount coil. Controlling the magnetic field strength leads to change the magnetorheological liquid properties and thereby the gene...

This paper reports an analytical method to show the effect of electrostatic and Casimir forces on the pull-in instability and vibration of single nano-plate (SNP) carrying a moving nanoparticle. Governing equations for nonlocal forced vibration of the SNP under a moving nanoparticle considering electrostatic and Casimir forces are derived by using Hamilton’s principle for the case when two ends...

Statistical vibroacoustics, also called statistical energy analysis (SEA) in the field of engineering, is born from the application of statistical physics concepts to the study of random vibration in mechanical and acoustical systems. This article is a discussion on the thermodynamic foundation for that approach with particular emphasis devoted to the meaning of entropy, a concept missing in SE...