The ineluctable change to micro and subsequently nano has engendered the need for precision control and actuation. With Piezoelectric technology at the heart, a new type of motor is improving small-scale motion systems in a big way. In the following study a novel design of a travelling-wave-type motor based on flexural excitations (d-15 effect) is analyzed using finite element method. The objec...

The use of distinguishable complex vibrations that have multiple spectral components can improve the transfer of information by vibrotactile interfaces. We investigated the qualitative characteristics of dual-frequency vibrations as the simplest complex vibrations compared to single-frequency vibrations. Two psychophysical experiments were conducted to elucidate the perceptual characteristics o...

Noise immissions with predominant low frequency sound components may exert considerably disturbing effects in dwellings. This applies in particular to sounds which are excitated by transmission of structure-borne noise, and to low frequency sounds emitted by ventilators. Exposed persons usually declare such immissions as being "intolerable" even at very low A-weighted sound levels. If mechanica...

The aim of this paper is to design a robust output-feedback controller to eliminate torsional stick-slip vibrations. A multi-modal model of the torsional dynamics with a nonlinear bit-rock interaction model is used. The controller design is based on skewed-μ DK-iteration and the stability of the closed-loop nonlinear system is analyzed. The proposed controller design strategy offers significant...

In the Structural Dynamics and Acoustics group at the University of Twente, we aim to develop a quantitative tyre/road noise model. An essential part of this model is an accurate contact algorithm which is fast enough to simulate tyre vibrations up to the acoustic frequencies. In this paper we present a contact algorithm, describing the contact between a tyre and a road surface, which has the p...

impact pile driving is a multi-component problem which is associated to multi-directional ground vibrations. at first, vibration is transferred from the hammer to the pile and then to the common interface of pile and soil. this is then transferred to the environment and has great impact on the adjacent structures, causing disturbance to residents and also damage to the buildings. it is of high ...

A new system was designed to selectively control cellular adhesion to medical implants. The system is based on magnetoelastic (ME) materials that can be remotely set to generate mechanical vibrations at submicron levels with predetermined amplitude and frequency. Previous studies have demonstrated the capacity of these vibrations to control cellular adhesion at a substrate surface. In this work...

Vertical vibrations at the slider leading edge exited by a disk asperity were investigated in a drive level system, using laser Doppler vibrometry and acoustic emission (AE) sensors. The flying height change at the leading edge of a thermal flying-height control slider was measured for different power inputs to the heater element. The maximum spacing change at the slider leading edge was found ...

in this paper deflection and free vibration of sandwich panel is studied. the core of sandwich panels is made of hexagonal honeycomb and faces are made of two different materials of carbon fiber reinforced plastic and k-aryl/epoxy covering. the governing equations are deduced from the first order sheer deformation theory (fsdt) and they are solved using generalized differential quadrature metho...

In the current study, the effect of such parameters as the length, position and angle of crack on free vibrations of a cracked plate was examined by finite element method. The assumed crack was internal and through and its growth was ignored. In the proposed finite element model, crack was considered as a discontinuity on the plate surface and the results were compared with the results of other...