Results 331 to 340 of about 13,819,893 (380)

Beam-Plasma Structures at Propagation of Electron Beams in Plasma

Physica Scripta, 1998
In the frame of the theory of weak turbulence the propagation of electron beams is considered. Using the smallness of quasilinear time transition from kinetic equations to gas-dynamic ones has been done. The obtained gas-dynamic equations are solved for one, two and N monoenergetic beams. It is shown that each beam generally propagates as a beam-plasma
Eduard P. Kontar, Valentin Melnik
openaire   +2 more sources

Vibration of Beam Structures

1991
We treat the dynamics of beams in a manner similar to that for rods. The sequence of analysis followed is: derive the governing differential equations, use spectral analysis to obtain general solutions, obtain an exact matrix formulation, obtain an approximate matrix formulation.
openaire   +2 more sources

Fault identification in beam structures

Journal of the Franklin Institute, 1992
Abstract A methodology based on the measurements of the natural frequencies of the structural system is developed for identification of the magnitude and location of the material defects and/or cracks. The numerical procedure is based on the matrix-transfer technique in which the dynamic characteristics of the system are related from one end to the ...
Fred K. Choy, P. Xu, Robert Y. Liang
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Structured beams in laser refractography [PDF]

Journal of Communications Technology and Electronics, 2009
The main types of structured laser beams obtained using diffractive optical elements are presented. A new information and measuring technique—the laser refractography based on the application of structured radiation—is proposed for the quantitative diagnostics of inhomogeneous media.
openaire   +1 more source

Band gaps in a periodic electro-elastic composite beam structure incorporating microstructure and flexoelectric effects

Archive of applied mechanics (1991), 2022
G. Y. Zhang, Z. Z. He, X.-L. Gao, H. W. Zhou   +3 more
semanticscholar   +1 more source

Nonlinear vibration analysis of a generally restrained double-beam structure coupled via an elastic connector of cubic nonlinearity

Nonlinear dynamics, 2022
Yuhao Zhao, Jingtao Du
semanticscholar   +1 more source

Hardware-in-the-loop optimization of an active vibration controller in a flexible beam structure using evolutionary algorithms

, 2014
In this study, active vibration control of a cantilevered flexible beam structure equipped with bonded piezoelectric sensor/actuators is investigated. The linear quadratic regulator technique together with an observer is adopted to design the controller ...
H. Nobahari, S. A. Hosseini Kordkheili, Sajad Saraygord Afshari   +2 more
semanticscholar   +1 more source

Variable stiffness type magnetic vibration absorber to control the vibration of beam structure

, 2014
Vibration absorbers are frequently used to control and minimize excess vibration in structural systems. Dynamic vibration absorbers are used to reduce undesirable vibration in many applications such as pumps, gas turbines, engines, bridges, electrical ...
F. Sayyad, N. Gadhave
semanticscholar   +1 more source

Increase in laser beam resistance to random inhomogeneities of atmospheric permittivity with an optical vortex included in the beam structure.

Applied Optics, 2012
The role of the vortical phase in the initial structure of the wave field of a laser beam propagating in the turbulent atmosphere in statistical regularities of beam wandering is studied.
V. Aksenov, C. Pogutsa
semanticscholar   +1 more source

Structurally Stable Hyperbolic Beam

Japanese Journal of Applied Physics, 2009
A technique for generation of a structurally stable hyperbolic beam using Fourier transform holography is reported. Bessel function with their arguments having hyperbolic locus is used for generating a diffractive optical element (DOE). For the introduction of optical vortex a circular vortex term is used.
Ajay Ghosh, Rijuparna Chakraborty
openaire   +2 more sources