Harmonic Wave Propagation in a Periodically Layered, Infinite Elastic Body: Plane Strain, Numerical Results

1980 ◽  
Vol 47 (3) ◽  
pp. 531-537 ◽  
Author(s):  
T. J. Delph ◽  
G. Herrmann ◽  
R. K. Kaul
Keyword(s):  
Wave Propagation ◽  
Plane Strain ◽  
Elastic Body ◽  
Harmonic Wave ◽  
Numerical Results ◽  
Analytical Properties

Numerical results are presented for the dispersion spectrum for harmonic wave propagation in an unbounded, periodically layered elastic body in a state of plane strain. Both real and complex branches are considered. The spectrum is shown to be multiple-valued and quite intricate in detail. Some analytical properties of the Floquet surface are also discussed.

Harmonic Wave Propagation in a Periodically Layered, Infinite Elastic Body: Plane Strain, Analytical Results

1979 ◽  
Vol 46 (1) ◽  
pp. 113-119 ◽  
Author(s):  
T. J. Delph ◽  
G. Herrmann ◽  
R. K. Kaul
Keyword(s):  
Wave Propagation ◽  
Asymptotic Behavior ◽  
Plane Strain ◽  
Elastic Body ◽  
Harmonic Wave ◽  
Wave Number ◽  
Periodic Medium ◽  
Frequency Wave ◽  
Wave Numbers ◽  
Band Characteristic

The problem of harmonic wave propagation in an unbounded, periodically layered elastic body in a state of plane strain is examined. The dispersion spectrum is shown to be governed by the roots of an 8 × 8 determinant, and represents a surface in frequency-wave number space. The spectrum exhibits the typical stopping band characteristic of wave propagation in a periodic medium. The dispersion equation is shown to uncouple along the ends of the Brillouin zones, and also in the case of wave propagation normal to the layering. The significance of this uncoupling is examined. Also, the asymptotic behavior of the spectrum for large values of the wave numbers is investigated.

scholarly journals Modeling of Harmonic Wave Propagation Through a Metasurface with Helmholtz Resonator Shaped Cells

2021 ◽  
Vol 2117 (1) ◽  
pp. 012002
Author(s):  
A Y Ismail ◽  
B Y Koo
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Wave Propagation ◽  
Harmonic Wave ◽  
Helmholtz Resonator ◽  
Numerical Results ◽  
Shape Design ◽  
The Finite Element Method ◽  
Parametric Studies ◽  
Engineering Practices

Abstract Harmonic wave propagation through a novel metasurface design is presented in this paper. The metasurface is formed by using the Helmholtz resonator as the cells shape design since such resonator has uniqueness and advantageous performances. The study is conducted both numerically using the finite element method and experimentally using specific measurements to validate the numerical results. Parametric studies of the selected variables are also conducted to obtain broader information on the performance. From the result, it is found that the new proposed metasurface design has the potential to be implemented in future engineering practices.

Harmonic Wave Propagation in a Periodically Layered, Infinite Elastic Body: Antiplane Strain

1978 ◽  
Vol 45 (2) ◽  
pp. 343-349 ◽  
Author(s):  
T. J. Delph ◽  
G. Herrmann ◽  
R. K. Kaul
Keyword(s):  
Wave Propagation ◽  
Elastic Medium ◽  
Elastic Body ◽  
Dispersion Equation ◽  
Harmonic Wave ◽  
Wave Number ◽  
Harmonic Waves ◽  
Antiplane Strain ◽  
Frequency Wave ◽  
Asymptotic Values

The propagation of horizontally polarized shear waves through a periodically layered elastic medium is analyzed. The dispersion equation is obtained by using Floquet’s theory and is shown to define a surface in frequency-wave number space. The important features of the surface are the passing and stopping bands, where harmonic waves are propagated or attenuated, respectively. Other features of the spectrum, such as uncoupling at the ends of the Brillouin zones, conical points, and asymptotic values at short wavelengths, are also examined.

scholarly journals Wave propagation in micropolar monoclinic thermoelastic half space

2013 ◽  
Vol 18 (4) ◽  
pp. 1013-1023
Author(s):  
R.R. Gupta
Keyword(s):  
Wave Propagation ◽  
Quality Factor ◽  
Plane Strain ◽  
Half Space ◽  
Numerical Results ◽  
Plane Strain Problem ◽  
Phase Velocities ◽  
Propagation Of Waves

Abstract Propagation of waves in a micropolar monoclinic medium possessing hermoelastic properties based on the Lord- Shulman (L-S),Green and Lindsay (G-L) and Coupled thermoelasticty (C-T) theories is discussed. The investigation is divided into two sections, viz., plane strain and anti-plane strain problem. After developing the solution, the phase velocities and attenuation quality factor have been derived and computed numerically. The numerical results have been plotted graphically.

A Numerical Analysis for Cracks Emanating from a Quarter-Spherical Cavity on the Edge of an Elastic Body

2012 ◽  
Vol 499 ◽  
pp. 243-247
Author(s):  
Long Hai Yan ◽  
Bao Liang Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Analysis ◽  
Elastic Body ◽  
Spherical Cavity ◽  
Numerical Results ◽  
Shielding Effect ◽  
Corner Crack ◽  
Element Method

This note is specifically concerned with cracks emanating from a quarter-spherical cavity on the edge in an elastic body (see Fig.1) by using finite element method. The numerical results show that the existence of the cavity has a shielding effect of the corner crack. In addition, it is found that the effect of boundaries parallel to the crack on the SIFs is obvious when.H/R≤3

Wave Propagation in Two-Dimensional Nonlinear Periodic Lattices

2009 ◽  
Author(s):  
Raj K. Narisetti ◽  
Massimo Ruzzene ◽  
Michael J. Leamy
Keyword(s):  
Wave Propagation ◽  
Linear Models ◽  
Periodic Structures ◽  
Harmonic Wave ◽  
Excitation Amplitude ◽  
Pass Band ◽  
Perturbation Approach ◽  
Nonlinear Stiffness ◽  
Two Dimensional ◽  
Low Amplitude

This paper investigates wave propagation in two-dimensional nonlinear periodic structures subject to point harmonic forcing. The infinite lattice is modeled as a springmass system consisting of linear and cubic-nonlinear stiffness. The effects of nonlinearity on harmonic wave propagation are analytically predicted using a novel perturbation approach. Response is characterized by group velocity contours (derived from phase-constant contours) functionally dependent on excitation amplitude and the nonlinear stiffness coefficients. Within the pass band there is a frequency band termed the “caustic band” where the response is characterized by the appearance of low amplitude regions or “dead zones.” For a two-dimensional lattice having asymmetric nonlinearity, it is shown that these caustic bands are dependent on the excitation amplitude, unlike in corresponding linear models. The analytical predictions obtained are verified via comparisons to responses generated using a time-domain simulation of a finite two-dimensional nonlinear lattice. Lastly, the study demonstrates amplitude-dependent wave beaming in two-dimensional nonlinear periodic structures.

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