Vibration tests are widely employed in many industrial fields, and in particular in aerospace industry to evaluate the mechanical behavior of parts for aircrafts and satellites. Usually, these tests are carried out with shakers, while inertial accelerometers are used to measure the shaker table acceleration from which the vibration amplitude is computed. Some applications require the measuremen...

This paper presents a novel real-time crack identification method to determine the position and depth of a transverse open crack on a rotating shaft. A newly developed wireless sensor capable of being mounted directly on the shaft can be employed to monitor acceleration at different points of a shaft in a rotating coordinate system. The vibration parameters obtained from a Finite Element Model ...

Fluid motion and pressure fields induced by vibrating spheres are frequently used to investigate the function of biological mechanosensory systems and artificial sensors. The calibration of the sphere motion amplitude (displacement, velocity, acceleration), time course and vibration direction often demands expensive equipment. To mitigate this requirement, we have developed a high-quality, low-...

Because the underlying physiology of pathological tremor in a Parkinson's patient is not well understood, the existing physical and drug therapies have not been successful in tremor treatment. Different mathematical modeling of such vibration has been introduced to investigate the problem and reduce the existing vibration. Most of the models have represented the induced vibration as a sinusoida...

The design of tall buildings, while concerned with efficiently and effectively carrying the anticipated loads imposed upon the structures, is largely concerned with serviceability and habitability issues. The latter issue may still require attention, even for buildings designed to meet lateral drift requirements (Kareem et al. 1999). As such, structural accelerations, as a function of return pe...

High cycle fatigue (HCF) cracks generated by compressor blade vibrations are a common source of failure in gas turbine engines. Current methods for crack detection are costly, time consuming, and prone to errors. In-situ blade vibration detection would help operators avoid critical engine speeds, and help infer the presence of cracks via a change in the mode of a blade. Blade vibrations can be ...

The causes of vibration hazards to motorcycle mail deliverers have been considered to be due to the vibrations from the motorcycle, strain on the rider's hands and arms, cold conditions, and duration of the operation and others, and the rider's muscle tone in handling the motorcycle rises as the stability of the motorcycle decreases. In this report, the steering angle and banking of the motorcy...

UNLABELLED This study determined how backrest inclination and the frequency and magnitude of vertical seat vibration influence vibration discomfort. Subjects experienced vertical seat vibration at frequencies in the range 2.5-25 Hz at vibration magnitudes in the range 0.016-2.0 ms(-2) r.m.s. Equivalent comfort contours were determined with five backrest conditions: no backrest, and with a stati...

Foam injection is widely applied in amounts of fields to drilling, production, and formation protection. Sometimes, the application result is disappointing, which is caused by the failure of bubble generation in foam flooding. Therefore, it is necessary to seek ways for improving the performance of foam injection. An increased disturbance to the stratum, like the vibration caused by a seismic o...