BACKGROUND Ultrasonic motors (USM) are based on the concept of driving the rotor by a mechanical vibration excited on the stator via piezoelectric effect. USM exhibit merits such as simple structure, quick response, quiet operation, self-locking when power off, nonelectromagnetic radiation and higher position accuracy. PRINCIPAL FINDINGS A cylindrical type traveling wave ultrasonic motor usin...

Supine human response and vibration-suppression during whole-body vibration." MS (Master of Science) thesis, ii ACKNOWLEDGMENTS I would like to acknowledge the U.S. Army Aberdeen Test Center (ATC) for the use of the inertial sensors, the USA Army Research Lab (USAARL) for providing the litter, Dr. David Wilder for providing the long spinal board and cervical collar, Mr. Jonathan DeShaw for assi...

This paper investigates the coupled axial-radial (CAR) vibration of single-walled carbon nanotubes (SWCNTs) based on doublet mechanics (DM) with a scale parameter. Two coupled forth order partial differential equations that govern the CAR vibration of SWCNTs are derived. It is the first time that DM is used to model the CAR vibration of SWCNTs. To obtain the natural frequency and dynamic respon...

In the process of geo-energy drilling, real-time vibration measurement drill pipes is significance for an understanding downhole conditions and properties rock. However, sensors used in areas at present require additional power sources, such as batteries, replacing batteries would significantly reduce production efficiency increase costs. our work, a new method using triboelectric nanogenerator...

The effect of the nonlocal parameter on free vibration analysis nano scaled trusses and frames is examined. Accordingly, firstly, axial bending vibrations longitudinal element are formulated. Simple rod Euler-Bernoulli assumptions considered for vibrations, respectively. Finite matrices obtained by applying average weighted residue to equation motion vibration. These combined according freedoms...

A kind of shape memory alloy (SMA) hysteretic nonlinear model is developed, and the stochastic bifurcation characteristics of SMA intravascular stents subjected to radial and axial excitations are studied in this paper. A new nonlinear differential item is introduced to interpret the hysteretic phenomena of SMA strain-stress curves, and the dynamic model of SMA intravascular stent subjected to ...

Cables, such as are used in cable-stayed bridges, suspension bridges, guy wires, transmission lines, and flexible space structures, are prone to vibration due to their low inherent damping characteristics. The mitigation of cable vibration is necessary to minimize negative impact. Transversely-attached passive viscous dampers have been implemented on some cables to dampen vibration. However, it...

Predicting and mitigating unwanted vibration of drillstrings is an important subject for oil drilling companies. Uncontrolled vibrations cause premature failure of the drillstring and associated components. The drillstring is a long slender structure that vibrates in three primary coupled modes: torsional, axial and transverse. Among these coupled modes, the transverse mode is the major cause o...

Use of uni-axial accelerometer is simplest and cost effective way to monitor vibration in a single direction. Situation in which, fault is rotating/changing its direction extraction of defect frequency is difficult from it. However, some of the bursts can be properly analysed. The acoustic sensor is another cost effective device which is generally omnidirectional and can be used in identificati...

We present an interference confocal microscope (ICM) with a new single-body four-step simultaneous phase-shifter device designed to obtain high immunity to vibration. The proposed ICM combines the respective advantages of simultaneous phase shifting interferometry and bipolar differential confocal microscopy to obtain high axis resolution, large dynamic range, and reduce the sensitivity to vibr...