in this paper, natural frequencies of the sandwich plates with soft flexible core and composite face sheets are obtained. three-dimensional (3d) finite element method (fem) is used for constructing and analyzing of the sandwich plates to obtain their natural frequencies. continuity conditions for transverse shear stresses at the interfaces as well as transverse flexibility and transverse normal...

In recent years, acoustic emission (AE) sensors and AE-based techniques have been developed and tested for gearbox fault diagnosis. In general, AE-based techniques require much higher sampling rates than vibration analysis-based techniques for gearbox fault diagnosis. Therefore, it is questionable whether an AE-based technique would give a better or at least the same performance as the vibratio...

The vibration problems of uniform and nonuniform Euler-Bernoulli beams have been solved analytically or approximately [1-5] for various end conditions. In order to calculate fundamental natural frequencies and related mode shapes, well known variational techniques such as Rayleigh_Ritz and Galerkin methods have been applied in the past. Besides these techniques, some discretized numerical metho...

Vibration problems in rotors can be extremely frustrating and may lead to greatly reduced reliability. By utilizing the proper data collection and analysis techniques, the faults because of vibration can be discovered and predicted. The signal analysis is important in extracting fault characteristics in fault diagnosis of machinery. The traditional signal analysis can not settle for non-station...

Holographic interferometry was used to study the vibration modes of a C4 handbell. Holographic interferograms were made of four of the vibration modes of the bell. Finite element analysis was used to create a preliminary model of the bell.

transmission of blast waves is a complex phenomenon and the characteristics vary with blast design parameters and geo-technical properties of medium. frequency of vibration and triggering component for structural excitation generally quantifies safe vibration magnitude. at closer distance or higher elevations than the blast locations, vertical or transverse component will be the first arrival t...

UNLABELLED The internationally accepted limit values and the health effects of hand-transmitted vibration exposure have been described extensively in the literature from temperate climate countries but not from a tropical climate environment. OBJECTIVES We conducted a systematic review of the health effects of hand-transmitted vibration exposure in tropical countries to determine the characte...

Mechanical-electrical analogous circuit models are widely used in electromechanical system design as they represent the function of a coupled electrical and mechanical system using an equivalent electrical system. This research uses electrical circuits to establish a discussion of simple active vibration control principles using two scenarios: an active vibration isolation system and an active ...

In recent years, improvement has been achieved in vibration signal processing, using wavelet analysis for condition monitoring and fault diagnosis. The use of wavelet analysis has proven to be efficient to detect faults in vibration signals with nonstationary, transient characteristics/ components. An experimental data set is used to compare the diagnostic capability of the fast Fourier transfo...

the subjective of this study was to explore and compare the effects of whole body vibration (wbv) and conventional spinal stabilization exercises on persons with non-specific chronic low back pain (clbp). thirty patients with non-specific chronic low back pain randomly received 6 sessions of spinal stabilization therapy with and without whole body vibration over 2 weeks. the severity of pain, f...