Wave Propagation Feature in Two-Dimensional Periodic Beam Lattices with Local Resonance by Numerical Method and Analytical Homogenization Approach

2018 ◽  
Vol 10 (04) ◽  
pp. 1850042 ◽  
Author(s):  
C. W. Zhou ◽  
X. K. Sun ◽  
J. P. Lainé ◽  
M. N. Ichchou ◽  
A. Zine ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Homogenization Method ◽  
Two Dimensional ◽  
Local Resonance ◽  
Homogenization Approach ◽  
Discrete Media ◽  
The Waves ◽  
Locking Phenomena ◽  
Analytical Homogenization ◽  
Propagation Feature

In this paper, the analytical homogenization method of Periodic Discrete Media (HPDM) and the numerical Condensed Wave Finite Element Method (CWFEM) are employed to study the wave propagation in two-dimensional periodic beam lattices. The validity of the HPDM is re-evaluated using the wave propagation feature identified by the CWFEM. Particular attention is paid to the polarization direction of the waves. The wave propagation in two directions is investigated while characteristic wave propagation features such as local resonance, veering and locking phenomena are observed. Complementary results are deduced from the two methods.

Numerical study of Love wave propagation

Geophysics ◽  
1983 ◽  
Vol 48 (7) ◽  
pp. 833-853 ◽  
Author(s):  
K. R. Kelly
Keyword(s):  
Numerical Modeling ◽  
Wave Propagation ◽  
Love Wave ◽  
Fourier Transforms ◽  
Narrow Band ◽  
Numerical Study ◽  
Two Dimensional ◽  
Band Pass ◽  
The Waves ◽  
Insight Into

Love wave propagation is studied by investigating numerical modeling results for several examples of geologic interest. The modal characteristics of the results are clarified by the use of narrow band‐pass filters and two‐dimensional Fourier transforms in range and time. Such processing makes it possible to study changes in phase and group velocity for the various modes and to locate points of reflection. This permits one to gain insight into changes in the physical properties of the surface channel supporting the waves.

scholarly journals Studi Penjalaran Gelombang Laut di Pulau Panjang, Kabupaten Jepara

2021 ◽  
Vol 10 (1) ◽  
pp. 75-87
Author(s):  
Tri Widya Laksana Putra ◽  
Muhammad Zainuri ◽  
Denny Nugroho Sugianto
Keyword(s):  
Wave Propagation ◽  
Direct Measurement ◽  
Hydrodynamic Model ◽  
High Tide ◽  
Acoustic Doppler Current Profiler ◽  
Wind Data ◽  
Two Dimensional ◽  
Single Beam ◽  
Current Profiler ◽  
The Waves

Pulau Panjang terletak di sebelah barat pantai Kota Jepara memiliki luas wilayah teritorial 30 Ha dan dimanfaatan sebagai wisata pulau, wisata ziarah, dan lokasi penangkapan ikan. Kombinasi kondisi gelombang ekstrim dan air pasang mengakibatkan tekanan kuat di pesisir Pulau Panjang sehingga menimbulkan kerusakan pada fasilitas wisata. Berdasarkan hal tersebut, diperlukan adanya analisis mengenai karakteristik penjalaran gelombang laut untuk menunjang segala jenis kegiatan masyarakat. Analisis penjalaran gelombang dilakukan melalui pendekatan pemodelan numerik hidrodinamika dua dimensi (two-dimensional hydrodynamic model). Data primer yang digunakan adalah data pengukuran langsung nilai gelombang menggunakan instrument Acoustic Doppler Current Profiler dan pengukuran langsung data batimetri menggunakan instrument single-beam echosounder. Data sekunder meliputi data angin (1999 – 2019) yang didapatkan dari portal unduh data di www.ogimet.com, data pasang surut BMKG dan data batimetri dari Badan Informasi Geospasial. Tinggi gelombang signifikan (Hs) dan periode signifikan (Ts) didapatkan dari konversi data angin menjadi nilai Hs dan Ts dengan metode DNS. Nilai Hs dan Ts maksimal setiap arah mata angin mmenjadi input perhitungan model hidrdodinamika. Hasil spasial penjalaran gelombang tertinggi terjadi pada arah datang gelombang dari arah timur laut, tenggara dan barat.  Penjalaran gelombang di Pulau Panjang menciptakan daerah terlindung di sisi seberang dari arah datang gelombang dan saat gelombang endekati pantai penjalaran gelombang mengikuti kontur garis pantai diikuti dengan melemahnya kecepatan rambat gelombang. Panjang Island is located on the west coast of Jepara City and has a territorial area of 30 hectares and is used as island tourism, pilgrimage tours, and fishing locations. The combination of extreme wave conditions and high tide resulted in strong force on the coast of Panjang Island causing damage to tourist facilities. Based on this, it is necessary to have an characteristics analysis of the sea waves propagation to support all types of community activities. Analysis of the propagation of the waves was carried out using a two-dimensional hydrodynamic model approach. The primary data used are direct measurement data of wave values using the Acoustic Doppler Current Profiler instrument and direct measurement of bathymetric data using a single-beam echosounder instrument. Secondary data includes wind data (1999 - 2019) obtained from the data download portal at www.ogimet.com, BMKG tidal data and bathymetry data from the Geospatial Information Agency. Significant wave height (Hs) and significant period (Ts) are obtained from the conversion of wind data into Hs and Ts values using the DNS method. The maximum Hs and Ts values for each cardinal direction are the input for calculating the hydrodynamic model. The highest spatial results of wave propagation occur in the coming direction of waves from the northeast, southeast and west. The wave propagation in Panjang Island creates a protected area on the opposite side from the direction of the waves coming and when the waves approach the coast the propagation of the waves follow the contours of the coastline followed by a weakening of the wave propagation speed.

Homogenization of very rough two-dimensional interfaces separating two dissimilar poroelastic solids with time-harmonic motions

2018 ◽  
Vol 24 (5) ◽  
pp. 1349-1367
Author(s):  
PC Vinh ◽  
DX Tung ◽  
NT Kieu
Keyword(s):  
Three Dimensional ◽  
Homogenization Method ◽  
Reflection And Transmission Coefficients ◽  
Two Dimensional ◽  
Matrix Formulation ◽  
Reflection And Transmission ◽  
Transmission Coefficients ◽  
Time Harmonic ◽  
The Matrix ◽  
Homogenization Approach

The homogenization of a very rough three-dimensional interface separating two dissimilar isotropic poroelastic solids with time-harmonic motions was considered by Gilbert and Ou (Acoustic wave propagation in a composite of two different poroelastic materials with a very rough periodic interface: A homogenization approach. Int J Multiscale Comput Eng 2003; 1(4): 431–440). The homogenized equations have been derived; however, they are still in implicit form. In this paper, the homogenization of a very rough two-dimensional interface separating two dissimilar generally anisotropic poroelastic solids with time-harmonic motions is investigated. The main aim of the investigation is to derive homogenized equations in explicit form. By employing the homogenization method, along with the matrix formulation of the poroelasticity theory, the explicit homogenized equations have been derived. Since these equations are totally explicit, they are very useful in solving practical problems. As an example proving this, the reflection and transmission of SH waves at a very rough interface of the tooth-comb type is considered. The closed-form analytical expressions of the reflection and transmission coefficients are obtained. Based on these expressions, the dependence of the reflection and transmission coefficients on some parameters is examined numerically.

Efficient Geometric Disassembly of Multiple Components from an Assembly Using Wave Propagation

2000 ◽  
Vol 122 (2) ◽  
pp. 179-184 ◽  
Author(s):  
Hari Srinivasan ◽  
Rajit Gadh
Keyword(s):  
Wave Propagation ◽  
Three Dimensional ◽  
Computation Time ◽  
Two Dimensional ◽  
New Approach ◽  
Multiple Components ◽  
Disassembly Sequence ◽  
Minimal Component ◽  
Selective Disassembly ◽  
The Waves

This paper analyzes the problem of disassembling multiple selected components from an assembly, defined as selective disassembly, and presents algorithms for efficient disassembly analysis of geometric models. Applications for selective disassembly include assembling, maintenance and recycling. A new approach called ‘Disassembly Wave Propagation’ is proposed to determine a selective disassembly sequence with minimal component removals from an assembly. This approach defines: (i) disassembly waves to topologically arrange the components denoting the disassembly order and (ii) intersection events between the waves to determine the selective disassembly sequences. In order to evaluate a minimal removal sequence in a feasible computation time, algorithms are proposed that prioritize and process the intersection events based on the order in which they occurred. The proposed algorithms analyze selective disassembly from the geometric perspective and are applicable for both two-dimensional and three-dimensional product assemblies. [S1050-0472(00)01402-1]

Acoustic wave propagation in two dimensional sheared ducted flows

1997 ◽  
Author(s):  
E. Longatte ◽  
P. Lafon ◽  
S. Candel ◽  
E. Longatte ◽  
P. Lafon ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Acoustic Wave ◽  
Two Dimensional ◽  
Acoustic Wave Propagation

scholarly journals Anomalous Anderson localization behavior in gain-loss balanced non-Hermitian systems

Nanophotonics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 443-452
Author(s):  
Tianshu Jiang ◽  
Anan Fang ◽  
Zhao-Qing Zhang ◽  
Che Ting Chan
Keyword(s):  
Wave Propagation ◽  
Electromagnetic Waves ◽  
Anderson Localization ◽  
Random Media ◽  
Normal Incidence ◽  
Disordered Media ◽  
One Dimensional ◽  
Gain Loss ◽  
The Waves ◽  
Localization Behavior

AbstractIt has been shown recently that the backscattering of wave propagation in one-dimensional disordered media can be entirely suppressed for normal incidence by adding sample-specific gain and loss components to the medium. Here, we study the Anderson localization behaviors of electromagnetic waves in such gain-loss balanced random non-Hermitian systems when the waves are obliquely incident on the random media. We also study the case of normal incidence when the sample-specific gain-loss profile is slightly altered so that the Anderson localization occurs. Our results show that the Anderson localization in the non-Hermitian system behaves differently from random Hermitian systems in which the backscattering is suppressed.

scholarly journals Study on X-ray Induced Two-Dimensional Thermal Shock Waves in Carbon/Phenolic

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3553
Author(s):  
Dengwang Wang ◽  
Yong Gao ◽  
Sheng Wang ◽  
Jie Wang ◽  
Haipeng Li
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Wave Propagation ◽  
Thermal Shock ◽  
Anisotropic Material ◽  
Energy Deposition ◽  
X Rays ◽  
Two Dimensional ◽  
X Ray ◽  
Deposition Depth

Carbon/Phenolic (C/P), a typical anisotropic material, is an important component of aerospace and often used to protect the thermodynamic effects of strong X-ray radiation. In this paper, we establish the anisotropic elastic-plastic constitutive model, which is embedded in the in-house code “RAMA” to simulate a two-dimensional thermal shock wave induced by X-ray. Then, we compare the numerical simulation results with the thermal shock wave stress generated by the same strong current electron beam via experiment to verify the correctness of the numerical simulation. Subsequently, we discuss and analyze the rules of thermal shock wave propagation in C/P material by further numerical simulation. The results reveal that the thermal shock wave represents different shapes and mechanisms by the radiation of 1 keV and 3 keV X-rays. The vaporization recoil phenomenon appears as a compression wave under 1 keV X-ray irradiation, and X-ray penetration is caused by thermal deformation under 3 keV X-ray irradiation. The thermal shock wave propagation exhibits two-dimensional characteristics, the energy deposition of 1 keV and 3 keV both decays exponentially, the energy deposition of 1 keV-peak soft X-ray is high, and the deposition depth is shallow, while the energy deposition of 3 keV-peak hard X-ray is low, and the deposition depth is deep. RAMA can successfully realize two-dimensional orthotropic elastoplastic constitutive relation, the corresponding program was designed and checked, and the calculation results for inspection are consistent with the theory. This study has great significance in the evaluation of anisotropic material protection under the radiation of intense X-rays.

Effects of geometric and refractive index disorder on wave propagation in two-dimensional photonic crystals

2000 ◽  
Vol 62 (4) ◽  
pp. 5711-5720 ◽  
Author(s):  
A. A. Asatryan ◽  
P. A. Robinson ◽  
L. C. Botten ◽  
R. C. McPhedran ◽  
N. A. Nicorovici ◽  
...  
Keyword(s):  
Refractive Index ◽  
Wave Propagation ◽  
Photonic Crystals ◽  
Two Dimensional

scholarly journals Airglow Measurements of Gravity Wave Propagation and Damping over Kolhapur (16.5°N, 74.2°E)

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
R. N. Ghodpage ◽  
A. Taori ◽  
P. T. Patil ◽  
S. Gurubaran ◽  
A. K. Sharma ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Gravity Wave ◽  
Meridional Wind ◽  
Vertical Wavelength ◽  
Emission Layer ◽  
Positive Correlation ◽  
Intensity Measurements ◽  
Wind Shears ◽  
The Waves ◽  
Airglow Intensity

Simultaneous mesospheric OH and O  (1S) night airglow intensity measurements from Kolhapur (16.8°N, 74.2°E) reveal unambiguous gravity wave signatures with periods varying from 01 hr to 9 hr with upward propagation. The amplitudes growth of these waves is found to vary from 0.4 to 2.2 while propagating from the OH layer (~87 km) to the O (1S) layer (~97 km). We find that vertical wavelength of the observed waves increases with the wave period. The damping factors calculated for the observed waves show large variations and that most of these waves were damped while traveling from the OH emission layer to the O (1S) emission layer. The damping factors for the waves show a positive correlation at vertical wavelengths shorter than 40 km, while a negative correlation at higher vertical wavelengths. We note that the damping factors have stronger positive correlation with meridional wind shears compared to the zonal wind shears.

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