In the present study, vortex-induced vibrations in both In-Line and Cross-Flow directions of long flexible cylinders within a uniform flow are predicted by modified wake oscillator model. detail, Van der Pol's model with drag lift coefficients being modelled as random variables. The statistics force coefficient, i.e. mean value standard deviation, extracted from literature reporting experimenta...

The aim of this study was to analyze electromyography (EMG) responses of vastus lateralis muscle to different whole-body vibration frequencies. For this purpose, 16 professional women volleyball players (age, 23.9 +/- 3.6 years; height, 182.5 +/- 11.1 cm; weight, 78.4 +/- 5.6 kg) voluntarily participated in the study. Vibration treatment was administered while standing on a vibrating platform w...

During the drilling process, sealing performance of roller cone bits is severely challenged by complex downhole environment and frequent vibrations. In this paper, a comprehensive thermal–fluid–solid–dynamic multi-field coupling numerical model new-generation single energizer metal seals (SEMS2) developed. The instantaneous SEMS2 studied under periodic vibration, shock, random vibration. Time-d...

where m is the mass of the particle and γ is the friction constant, (t) is the random force with zero mean and a nonzero variance. As an example let us mention a generalized Langevin equation describing dynamics of atoms interacting with thermal vibrations of the crystal lattice derived in Ref. [2]. Both the friction and the random force are very crude phenomenological substitutes of the real c...

We report a numerical study of the flexural modes of a plate using semi-classical analysis developed in the context of quantum systems. We first introduce the Clover billiard as a paradigm for a system inside which rays exhibit stable and chaotic trajectories. The resulting phase space explored by the ray trajectories is illustrated using the Poincare surface of section, and shows that it has b...

The propagation of sound waves and electromagnetic radiation in a background medium is strongly innuenced by the addition of random scatterers. We study random perturbations of a background medium which has a spectral gap in its permissible energy spectrum. We prove that the randomness localizes waves at energies near the band edges of the spectral gap of the background medium. The perturbation...

In the present paper, electrical energy harvesting from random vibrations of an Euler-Bernoulli nano-beam with two piezoelectric layers is investigated. The beam is composed of an aluminum layer together with two piezoelectric ceramic layers (PZT 5A) serving as energy harvesting sensors. In the proposed method, the equations governing the bimorph nano-beam will be analytically derived using cla...

We quantitatively interpret the recently discovered intriguing phenomenon related to resonance Hyper-Raman (HR) scattering. In resonance HR spectra of all-trans-β-carotene (β-carotene) in solution, vibrations of proximate solvent molecules are observed concomitantly with the solute β-carotene HR bands. It has been shown that these solvent bands are subject to marked intensity enhancements by mo...

The purpose of this mini-review is to outline diversity of chest wall vibrations, specify biomechanical peculiarities and point out a few problems crucial for development of diagnostic and therapeutic applications of chest wall vibrations. The review considers two types of chest wall vibrations: spontaneous, induced by breathing, and forced (or artificial), induced by external vibration forces....

This article discusses the research of one urgent problems transportation binding materials by cars on domestic highways. The study examined oscillations disturbing forces, as well main sources disturbances cars, i.e. road surface bumps; eccentricity, uneven movement and imbalance wheels; rotating parts engine; transmissions. idea dependence vehicle vibrations a with an is traced, while usually...