Dispersion characteristics of surface magnetostatic wave with dissipation

2016 ◽  
Author(s):  
Герус ◽  
Sergey Gerus ◽  
Анненков ◽  
A. Annenkov
Keyword(s):  
Dispersion Curve ◽  
Wave Number ◽  
Magnetostatic Wave ◽  
Dispersion Characteristics ◽  
High Attenuation ◽  
Inverse Dispersion ◽  
Maximum Value ◽  
Surface Wave Propagation ◽  
Surface Magnetostatic Wave ◽  
Dispersion Branch

It is shown that the dispersion characteristics of spin surface waves with dissipation unlike undamped waves have the wave number maximum value at which there is a reversal in the dispersion curve of wavenumber downward. This forms the upper branch of the dispersion curve with the inverse dispersion and high attenuation, which gives rise to ambiguous depending on the frequency of the wave vector. Lower primary dispersion branch corresponds to waves with a direct dispersion, attenuation is proportional to the small parameter of dissipation. However, near the wave number maximum value the attenuation coefficient of the waves sharply increases. Some angular and frequency limits of the of surface wave propagation are changed as well.

scholarly journals Sabot Front Borerider Stiffness vs. Dispersion: Finding the Knee in the Curve

2001 ◽  
Vol 8 (3-4) ◽  
pp. 193-201 ◽  
Author(s):  
Alan F. Hathaway ◽  
John R. Burnett Jr.
Keyword(s):  
Dispersion Curve ◽  
Analytical Approach ◽  
Design Consideration ◽  
Dispersion Characteristics ◽  
Radial Stiffness ◽  
The Subject ◽  
Important Design

In the design of armor piercing, fin-stabilized, discarding sabot projectiles, the radial stiffness of the sabot front borerider has a significant impact on the projectile's dispersion and is, therefore, an important design consideration. Whether designing a new projectile or trying to improve an existing design, projectile designers can achieve front borerider stiffness without understanding its affect on dispersion characteristics. There is a knee in the stiffness vs. dispersion curve at which a change in the sabot front borerider stiffness will have a significant impact on dispersion or no impact at all depending on whether the stiffness is increased or decreased. The subject of this paper is an analytical approach to quantitatively determine the knee in the curve. Results from using this approach on the M865 APFSDS projectile are also presented.

scholarly journals Defects Detection and Localization in Underwater Plates Using Laser Laterally Generated Pure Non-Dispersive S0 Mode

2019 ◽  
Vol 9 (3) ◽  
pp. 459 ◽  
Author(s):  
Qingnan Xie ◽  
Chenyin Ni ◽  
Zhonghua Shen
Keyword(s):  
Defect Detection ◽  
Lamb Waves ◽  
Mode Conversion ◽  
High Sensitivity ◽  
Laser Source ◽  
Dispersion Characteristics ◽  
High Attenuation ◽  
Corrosion Defects ◽  
Detection And Localization ◽  
Lateral Excitation

When working in humid environments, corrosion defects are easily produced in metallic plates. For defect detection in underwater plates, symmetric modes of Lamb waves are widely used because of their characteristics including long propagating distance and high sensitivity to defects. In this study, we extend our previous work by applying the laser laterally generated S0 mode to detection and localization of defects represented by artificial notches in an aluminum plate immersed in water. Pure non-dispersive S0 mode is generated in an underwater plate by lateral laser source irradiation and its fd (frequency·thickness) range is selected by theoretical calculation. Using this lateral excitation, the S0 mode is enhanced; meanwhile, the A0 mode is effectively suppressed. The mode-converted A0 mode from the incident S0 mode is used to detect and localize the defect. The results reveal a significantly improved capability to detect defects in an underwater plate using the laser laterally generated S0 mode, while that using A0 is limited due to its high attenuation. Furthermore, owing to the long propagating distance and the non-dispersion characteristics of the S0 generated by the lateral laser source, multiple defects can also be detected and localized according to the mode conversion at the defects.

scholarly journals Estimation of <i>Vs</i> profile using its natural frequency and Rayleigh-wave dispersion characteristics

2008 ◽  
Vol 14 ◽  
pp. 75-77 ◽  
Author(s):  
K. Tokeshi ◽  
M. Karkee ◽  
C. Cuadra
Keyword(s):  
Rayleigh Wave ◽  
Dispersion Curve ◽  
Natural Frequency ◽  
Numerical Test ◽  
Wave Dispersion ◽  
Test Site ◽  
Dispersion Characteristics ◽  
Rayleigh Wave Dispersion

Abstract. The evaluation of the natural frequency of random Vs profiles before analyzing the fundamental Rayleigh-wave dispersion characteristics is proposed in this paper. The inclusion of this parameter optimizes the effectiveness of random inverse searching to estimate Vs profiles. To demonstrate this method, a numerical test was performed using the "experimental" Rayleigh-wave dispersion curve obtained for a fictitious TEST site.

scholarly journals Управление свойствами спин-волнового транспорта в полукольцевом магнонном микроволноводе

2019 ◽  
Vol 89 (11) ◽  
pp. 1726
Author(s):  
В.А. Губанов ◽  
А.А. Мартышкин ◽  
С.Е. Шешукова ◽  
А.В. Садовников
Keyword(s):  
Wave Propagation ◽  
Spatial Distribution ◽  
Transmission Coefficient ◽  
Standing Waves ◽  
Waveguide Structure ◽  
Translational Symmetry ◽  
Magnetostatic Wave ◽  
Dynamic Magnetization ◽  
Wave Transport ◽  
Surface Magnetostatic Wave

AbstractSpin-wave transport along a waveguide structure with disturbed translational symmetry has been investigated. A semiring portion of a magnon microwaveguide has been made of a YIG film. It has been shown that one can control the dynamic magnetization spatial distribution by varying the magnetic biasing angle in the microwaveguide plane. Under such conditions, the transmission coefficient of standing waves changes noticeably. The structure suggested in this paper allows the rotation of spin-wave signals in an irregular configuration under the conditions of surface magnetostatic wave propagation. This effect may be used in planar magnon networks.

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