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Journal articles on the topic 'Propagation guidée'

Author: Grafiati

Published: 4 June 2021

Last updated: 18 February 2022

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1

Perrey-Debain, Emmanuel, Yves Gervais, and Michel Guilbaud. "Extension de la DRBEM à la propagation guidée en écoulement cisaillé." Comptes Rendus de l'Académie des Sciences - Series IIB - Mechanics 328, no. 5 (2000): 429–36. http://dx.doi.org/10.1016/s1620-7742(00)00040-4.

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2

GERVAIS, Y., and J. L. PEUBE. "PROPAGATION GUIDÉE EN PRÉSENCE DE CHAMPS DE VITESSE ET DE TEMPÉRATURE STRATIFIÉS." Le Journal de Physique IV 02, no. C1 (1992): C1–549—C1–552. http://dx.doi.org/10.1051/jp4:19921118.

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3

Escoubas, Ludovic, Stéphane Tisserand, and Alexandre Gatto. "The balance of losses in optical coatings by absorption and guided propogation attenuation measurements." Journal of Optics 29, no. 1 (1998): 40–48. http://dx.doi.org/10.1088/0150-536x/29/1/007.

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4

Kelebekler, Ersoy. "An analysis of leaky hybrid modes depending on structural parameters in a circular dielectric rod." Frequenz 75, no. 9-10 (2021): 377–87. http://dx.doi.org/10.1515/freq-2020-0189.

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Abstract Open dielectric waveguides are structures used to guide electromagnetic energy in integrated circuits above the cutoff or as leaky wave antennas propagating the energy transversely out of the waveguide in a narrow region below the cutoff. In this study, the related operating regions for the hybrid EH modes of a cylindrical dielectric rod were obtained analytically. Analyses of the leaky wave characteristics of the hybrid EH modes for various radii of the rod and various dielectric constant values were performed. The guided modes existing above the cutoff with a pure real propagation constant, and the leaky wave modes existing below the cutoff with a complex propagation constant, were obtained from the coefficient matrix of the characteristic equations system of the structure using the bisection method and Davidenko’s method, respectively. Additionally, the guided modes of the structure were obtained and designated in the light of previous studies in the literature. The results show that the frequency spectrum of the antenna mode region increases as the value of the dielectric constant and the radius of the dielectric rod decrease. In addition, a circular dielectric with a smaller radius and dielectric constant had a larger frequency spectrum in the leaky wave antenna applications.

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5

Su, Zhiyuan, Mingchu Li, Xinxin Fan, Xing Jin, and Zhen Wang. "Research on Trust Propagation Models in Reputation Management Systems." Mathematical Problems in Engineering 2014 (2014): 1–16. http://dx.doi.org/10.1155/2014/536717.

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Feedback based reputation systems continue to gain popularity in eCommerce and social media systems today and reputation management in large social networks needs to manage cold start and sparseness in terms of feedback. Trust propagation has been widely recognized as an effective mechanism to handle these problems. In this paper we study the characterization of trust propagation models in the context of attack resilience. We characterize trust propagation models along three dimensions: (i) uniform propagation and conditional propagation, (ii) jump strategies for breaking unwanted cliques, and (iii) decay factors for differentiating recent trust history from remote past history. We formally and experimentally show that feedback similarity is a critical measure for countering colluding attacks in reputation systems. Without feedback similarity guided control, trust propagations are vulnerable to different types of colluding attacks.

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6

Kažys, Rymantas, Egidijus Žukauskas, Liudas Mažeika, and Renaldas Raišutis. "Propagation of Ultrasonic Shear Horizontal Waves in Rectangular Waveguides." International Journal of Structural Stability and Dynamics 16, no. 08 (2016): 1550041. http://dx.doi.org/10.1142/s0219455415500418.

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The aim of this paper is to investigate the propagation of ultrasonic shear horizontal guided waves along waveguides with a rectangular cross-section and with a finite constant and variable width and to determine the peculiarities of propagation of those waves. The dispersion curves of guided waves in finite-width waveguides were modeled by using a semi-analytical finite element (SAFE) technique. The propagation of pulsed shear horizontal ultrasonic guided waves was investigated numerically by using 3D finite element modeling. It was found that in the case of finite-width waveguides, the SH0 shear horizontal wave splits into a family of SH-type dispersive modes propagating with different phase velocities. It was also found that the number of propagating modes depends on the width-to-thickness ratio. The first time spatial distributions of pulsed displacements across the waveguide were determined for waveguides of different widths. Investigation of the waveguides with a rectangular cross-section and varying lateral dimensions was performed. It was found that by properly selecting the geometry of the transient zone of waveguides with a rectangular cross-section, it is possible to improve the performance of such waveguides, e.g. to increase the amplitude of the transmitted pulse type signal without significant distortions of the waveforms.

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7

Biwa, Shiro, Yukiko Inoue, and Nobutada Ohno. "OS02W0060 Influence of contact pressure on guided wave propagation at contact interface." Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics 2003.2 (2003): _OS02W0060. http://dx.doi.org/10.1299/jsmeatem.2003.2._os02w0060.

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8

Yevick, D. "A guide to electric field propagation techniques for guided-wave optics." Optical and Quantum Electronics 26, no. 3 (1994): S185—S197. http://dx.doi.org/10.1007/bf00384672.

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9

Ma, Quan Wen, Zhong Yin Xiao, Xiao Xue Xu, Xiao Long Ma, De Jun Liu, and Zi Hua Wang. "Dispersion Curves and Fields for a Chiral Negative Refraction Parallel-Plate Waveguide under PMC Boundary." Applied Mechanics and Materials 571-572 (June 2014): 920–24. http://dx.doi.org/10.4028/www.scientific.net/amm.571-572.920.

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The characteristics of a chiral negative refraction parallel-plate waveguide under PMC boundary are studied theoretically, and the corresponding dispersion relations, cut-off frequencies, propagating guided modes are obtained. Some novel features are found, such as fundamental mode will be not exist only if the chirality parameter κ>1, in addition, the cutoff frequency is no longer the conventionally defined frequency when propagation constant is zero, but the least frequency that guided mode can still propagate. According to the relations between propagation constant β and wavenumbers k+,k-, the dispersion curves are divided into three regions , and the electromagnetic field components in the regions are analyzed in detail.

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10

Chen, Xiao. "Ultrasonic Guided Waves in Piezoelectric Layered Composite with Different Interfacial Properties." Advances in Materials Science and Engineering 2011 (2011): 1–7. http://dx.doi.org/10.1155/2011/701819.

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Combining the propagation model of guided waves in a multilayered piezoelectric composite with the interfacial model of rigid, slip, and weak interfaces, the generalized dispersion characteristic equations of guided waves propagating in a piezoelectric layered composite with different interfacial properties are derived. The effects of the slip, weak, and delamination interfaces in different depths on the dispersion properties of the lowest-order mode ultrasonic guided wave are analyzed. The theory would be used to characterize the interfacial properties of piezoelectric layered composite nondestructively.

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11

LEE, TAE-HUN, IK-HWANG CHOI, and KYUNG-YOUNG JHANG. "THE NONLINEARITY OF GUIDED WAVE IN AN ELASTIC PLATE." Modern Physics Letters B 22, no. 11 (2008): 1135–40. http://dx.doi.org/10.1142/s0217984908015966.

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The ultrasonic nonlinearity has been considered as a promising method to evaluate the material degradation, since it is sensitive to the minute variation of material properties. However, most researches were restricted to the nonlinear phenomena of bulk (longitudinal) wave propagation in the bulky medium. In the case of plate, however, the propagating elastic wave is Lamb wave of which characteristics are completely different with the bulk wave, and thus the separate study for the nonlinearity of Lamb wave is required. This paper reports the result of our basic study on the nonlinear phenomena of Lamb waves, which proposes conditions for practical application as well as for the cumulative propagation of quadratic harmonic frequency mode; (1) phase matching, (2) non-zero power flux, (3) group velocity matching, and (4) non-zero out-of-plane displacement.

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12

Zhu, Long Xiang, Yue Min Wang, and Feng Rui Sun. "Numerical Simulation on Detecting Defects in Pipes Using T(0,1) Mode Guided Wave." Advanced Materials Research 823 (October 2013): 456–60. http://dx.doi.org/10.4028/www.scientific.net/amr.823.456.

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The guided-wave technology is very efficient in inspecting a large portion of pipe. In order to study the propagation property of guided wave in pipe and the interaction between guided waves and defects, pipe model was established using 3D solid finite element in the software ANSYS. Tangential displacements were prescribed on the nodes in the pipe end and the propagating of T(0,1) mode guided wave in pipes was simulated. The detecting signals for the pipe model with different defects were extracted, which matched very well with experimental result.

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13

Marinescu, Nicolae, and Rudolf Nistor. "Quantum description of microwave passive circuits." Canadian Journal of Physics 68, no. 10 (1990): 1122–25. http://dx.doi.org/10.1139/p90-157.

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The paper gives a formal analogy between the distribution of the electromagnetic field in a wave guide and microwave cavities and the quantum-mechanical probabilities distribution. We show that the wave guide of the cutoff frequency ωc acts on an electromagnetic wave as a quantum potential barrier [Formula: see text]. We also establish a nonhabitual time-independent Schrödinger equation that replaces Maxwell's equations in describing guided wave propagation.

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14

Topa, António L., Carlos R. Paiva, and Afonso M. Barbosa. "Novel propagation features of double negative H-guides and H-guide couplers." Microwave and Optical Technology Letters 47, no. 2 (2005): 185–90. http://dx.doi.org/10.1002/mop.21119.

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15

Grillet, C., X. Letartre, C. Seassal, et al. "Propagation dans les guides d'ondes à cristaux photoniques et couplage guide-cavité." Journal de Physique IV (Proceedings) 12, no. 5 (2002): 277–79. http://dx.doi.org/10.1051/jp4:20020160.

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16

Bourdine, Anton. "Fast and Simple Method for Evaluation of Polarization Correction to Propagation Constant of Arbitrary Order Guided Modes in Optical Fibers with Arbitrary Refractive Index Profile." Mathematical Problems in Engineering 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/801243.

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This work presents fast and simple method for evaluation of polarization correction to scalar propagation constant of arbitrary order guided modes propagating over weakly guiding optical fibers. Proposed solution is based on earlier on developed modified Gaussian approximation extended for analysis of weakly guiding optical fibers with arbitrary refractive index profile in the core region bounded by single solid outer cladding. Some results are presented that illustrate the decreasing of computational error during the estimation of propagation constant when polarization corrections are taken into account. Analytical expressions for the first and second derivatives of polarization correction are derived and presented.

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17

Zhang, Pengfei, Zhifeng Tang, Fuzai Lv, and Keji Yang. "Numerical and Experimental Investigation of Guided Wave Propagation in a Multi-Wire Cable." Applied Sciences 9, no. 5 (2019): 1028. http://dx.doi.org/10.3390/app9051028.

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Ultrasonic guided waves (UGWs) have attracted attention in the nondestructive testing and structural health monitoring (SHM) of multi-wire cables. They offer such advantages as a single measurement, wide coverage of the acoustic field, and long-range propagation ability. However, the mechanical coupling of multi-wire structures complicates the propagation behaviors of guided waves and signal interpretation. In this paper, UGW propagation in these waveguides is investigated theoretically, numerically, and experimentally from the perspective of dispersion and wave structure, contact acoustic nonlinearity (CAN), and wave energy transfer. Although the performance of all possible propagating wave modes in a multi-wire cable at different frequencies could be obtained by dispersion analysis, it is ineffective to analyze the frequency behaviors of the wave signals of a certain mode, which could be analyzed using the CAN effect. The CAN phenomenon of two mechanically coupled wires in contact was observed, which was demonstrated by numerical guided wave simulation and experiments. Additionally, the measured guided wave energy of wires located in different layers of an aluminum conductor steel-reinforced cable accords with the theoretical prediction. The model of wave energy distribution in different layers of a cable also could be used to optimize the excitation power of transducers and determine the effective monitoring range of SHM.

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18

Li, Weibin, Mingxi Deng, and Younho Cho. "Cumulative Second Harmonic Generation of Ultrasonic Guided Waves Propagation in Tube-Like Structure." Journal of Computational Acoustics 24, no. 03 (2016): 1650011. http://dx.doi.org/10.1142/s0218396x16500119.

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Second harmonic generation of ultrasonic waves propagating in unbounded media and plate-like structure has been vigorously studied for tracking material nonlinearity, however, second harmonic guided wave propagation in tube-like structures is rarely studied. Considering that second harmonics can provide sensitive information for structural health condition, this paper aims to study the second harmonic generation of guided waves in metallic tube-like structures with weakly nonlinearity. Perturbation method and modal analysis approach are used to analyze the acoustic field of second harmonic solutions. The conditions for generating second harmonics with cumulative effect are provided in present investigation. Flexible polyvinylidene fluoride comb transducers are used to measure fundamental wave modes and second harmonic ones. The work experimentally verifies that the second harmonics of guided waves in pipe have a cumulative effect with propagation distance. The proposed procedure of this work can be applied to detect material nonlinearity due to damage mechanism in tube-like structure.

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19

Fruit, G., and P. Louarn. "On the propagation of MHD eigenmodes in a 2-D-magnetotail." Annales Geophysicae 29, no. 1 (2011): 19–30. http://dx.doi.org/10.5194/angeo-29-19-2011.

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Abstract. The propagation of MHD kink/sausage low frequency waves in the magnetotail with a finite normal Bz component is addressed. The general idea is to investigate how a finite Bz may affect the propagation of MHD eigenmodes in the plasma sheet. The standard MHD equations are linearized and solved numerically in a modified Harris sheet. Boundary conditions are chosen such that energy flows outward of the frame box (free propagating system). An initial perturbation is set up in the pressure gradient term and the wave energy is then traced in the system. While a pure 1-D-Harris sheet constitutes an efficient wave guide for MHD eigenmodes, the introduction of a finite Bz in the zero-order geometry changes significantly the propagation of MHD fluctuations: the eigenmodes propagate much more slowly and carry little energy whereas a pure sound wave is excited and propagates isotropically in the system. The presence of a finite Bz thus tends to inhibit the MHD propagation of energy along the plasma sheet. It tends rather to spread the energy throughout the magnetotail. As an application of the above study, the role of a permanent X-point structure on MHD propagation in the plasma sheet is also explored.

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20

Malinowski, Pawel, Tomasz Wandowski, and Wieslaw Ostachowicz. "Guided Waves for Aircraft Panel Monitoring." Key Engineering Materials 558 (June 2013): 107–15. http://dx.doi.org/10.4028/www.scientific.net/kem.558.107.

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The reported research concerns experimental investigation toward the monitoring of an aircraft panel. Guided wave propagation phenomena were used to obtain information about the state of the monitored structure. A curved aluminium panel with rivets was investigated. Piezoelectric transducer was used to excite guided waves in chosen structural element. The generated signal was amplified before applying it to the transducer in order to ensure measurable amplitude of excited guided waves. Measurement of the wave field was realized using laser scanning vibrometer that registered the velocity responses at a points belonging to a defined mesh. This contactless measurement technique allowed to investigate phenomena related to wave propagation in the aircraft panel. In the first stage, due to high complexity of the element, baseline measurements were taken. Next, a discontinuity (additional mass) was introduced on the panel surface and the measurements were repeated. Signal processing methods for features extraction from signals were proposed. These features were applied in order to detect and localize the presence anomalies in the investigated panel. The signal processing was conducted in MATLAB with the procedures developed by the authors. The used measurement technology (vibrometer) allowed to register whole wavefield of the propagating guided waves. This allowed to visualize the interaction of the waves with rivets. After introducing the discontinuity on the panel surface wave interaction with it was investigated. Two positions of the additional mass were considered. One just before the riveted stiffener and second after the stiffener. Because of this the influence of the stiffener on the damage detection abilities could be investigated. It can be concluded that the guided wave can be used for monitoring of such complex structures. The vibrometer measurements allowed learn about the guided wave propagation phenomena and perform successful damage localization.

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21

Salim, M. N., M. N. M. Khairy, and T. Hayashi. "Effect of Oval Defect on Propagation of Fundamental Lamb Wave." Applied Mechanics and Materials 833 (April 2016): 49–58. http://dx.doi.org/10.4028/www.scientific.net/amm.833.49.

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Complicated Lamb wave propagation in structures can cause a misinterpretation in defect location and sizing during nondestructive inspections. A visualization of Lamb wave interactions with oval defects was carried out in our study to investigate the phenomenon of fundamental Lamb wave interaction around defect by using a reduced model of plate in ABAQUS. The visualized wave propagations with oval shape of through defects in plates demonstrated different patterns of wave interactions for the symmetric and anti-symmetric modes. The results also visualized the mode conversions around defects which converted from the incident waves. The visualized changes on the wave structures due to wave interaction with defects is important to increase our understanding on the guided wave propagation and reduce misinterpretation in nondestructive inspection when using the wave modes during inspection on large structures.

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22

Gareeva, Z. V., and R. A. Doroshenko. "Shear Thickness Modes in a Presence of Magnetoelastic Waves Parallel to a Surface Guided by Ferromagnetic Film." Solid State Phenomena 152-153 (April 2009): 381–84. http://dx.doi.org/10.4028/www.scientific.net/ssp.152-153.381.

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Thickness modes of magnetoelastic waves (MEW) guided by ferromagnetic film have been investigated. Propagation of two mutually perpendicular MEW one of which is parallel to a normal to the surface has been considered. It has been shown that resonant frequencies of standing MEW depend on the wave number of a wave propagating along a surface. Plots illustrating dependence of thickness shear modes upon wave vector kz of MEW traveling in a surface plane have been presented.

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23

BÓDAI, TAMÁS, and MARIAN WIERCIGROCH. "ACOUSTIC RAY STABILITY FOR LONG-RANGE SOUND SPEED PROFILE TRANSITION SCENARIOS." International Journal of Bifurcation and Chaos 21, no. 01 (2011): 177–94. http://dx.doi.org/10.1142/s0218127411028350.

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Range-dependency in the background sound speed structure for deep ocean propagation scenarios is typical. Here a special case is considered when there is a gradual transition between single and double minimum sound speed profiles. Ray stability, an important measure for many applications, is analyzed. It is done by studying the unperturbed autonomous ray equations in the quasistatic limit. The wave guide is mapped out in terms of constant action curves in the vertical plane of propagation, which reveals a bifurcation effect in the studied wave guides. Conditions for the constancy or a sudden change of the action of a ray trajectory, an effect that impacts on the "use" of a ray, are given.

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24

Xia, J., P. P. Toulios, and C. Vittoria. "Propagation properties of ferromagnetic insulator guide." IEEE Transactions on Microwave Theory and Techniques 37, no. 10 (1989): 1547–54. http://dx.doi.org/10.1109/22.41000.

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25

Singh, Navpreet, and Arvinder Singh. "The effect of plasma channel on the self-distortion of laser pulse propagating through the collisionless plasma channel." Journal of Nonlinear Optical Physics & Materials 23, no. 03 (2014): 1450027. http://dx.doi.org/10.1142/s0218863514500271.

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This paper presents an investigation of the laser pulse distortion/breakup and the effect of the plasma channel on the laser propagation through the collisionless plasma. Moment theory has been used to derive differential equations of the beam width parameter of the laser propagating through uniform homogenous plasma and preformed plasma channel having parabolic density profile. Differential equations have been set up and solved numerically by using Runge Kutta method. From analysis, it is observed that the low intensity front and rear parts of the laser pulse get defocused/diffracted while the high intensity central portion of the laser pulse gets self-guided during the propagation through uniform homogenous plasma. As a result of this, laser pulse gets distorted. This distortion of the laser pulse has not been observed when the laser beam is propagated through the plasma channel having parabolic density profile. The laser pulse is guided as a whole, even the low intensity front and rear parts of the laser pulse are also guided. Therefore, it is predicted that plasma channel plays a significant role to prevent the distortion/beam breakup of the laser.

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26

Pagano, P., H. J. Van Damme, P. Antolin, and I. De Moortel. "MHD simulations of the in situ generation of kink and sausage waves in the solar corona by collision of dense plasma clumps." Astronomy & Astrophysics 626 (June 2019): A53. http://dx.doi.org/10.1051/0004-6361/201935539.

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Context. Magnetohydrodynamic (MHD) waves are ubiquitous in the solar corona where the highly structured magnetic fields provide efficient wave guides for their propagation. While MHD waves have been observed originating from lower layers of the solar atmosphere, recent studies have shown that some can be generated in situ by the collision of dense counter-propagating flows. Aims. In this theoretical study, we analyse the mechanism that triggers the propagation of kink and sausage modes in the solar corona following the collision of counter-propagating flows, and how the properties of the flows affect the properties of the generated waves. Methods. To study in detail this mechanism we ran a series of ideal 2D and 3D MHD simulations where we varied the properties of the counter-propagating flows; by means of a simple technique to estimate the amplitudes of the kink and sausage modes, we investigated their role in the generation and propagation of the MHD waves. Results. We find that the amplitude of the waves is largely dependent on the kinetic energy of the flows, and that the onset of kink or sausage modes depends on the asymmetries between the colliding blobs. Moreover, the initial wavelength of the MHD waves is associated with the magnetic configuration resulting from the collision of the flows. We also find that genuine 3D systems respond with smaller wave amplitudes. Conclusions. In this study, we present a parameter space description of the mechanism that leads to the generation of MHD waves from the collision of flows in the corona. Future observations of these waves can be used to understand the properties of the plasma and magnetic field of the solar corona.

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27

Shengyong, Xu, Peng Biye, Wu Haiyang, Li Fushuai, Cai Xingkui, and Duan Hongbing. "An Automatic Machine Vision-Guided System for the Propagation of Potato Test-Tube Plantlets." Journal of Robotics 2020 (May 26, 2020): 1–11. http://dx.doi.org/10.1155/2020/3562818.

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In manually propagating potato test-tube plantlets (PTTPs), the plantlet is usually grasped and cut at the node point between the cotyledon and stem, which is hardly located and is easily damaged by the gripper. Using an agricultural intelligent robot to replace manual operation will greatly improve the efficiency and quality of the propagation of PTTPs. An automatic machine vision-guided system for the propagation of PTTPs was developed and tested. In this paper, the workflow of the visual system was designed and the image acquisition device was made. Furthermore, the image processing algorithm was then integrated with the image acquisition device in order to construct an automatic PTTP propagation vision system. An image processing system for locating a node point was employed to determine a suitable operation point on the stem. A binocular stereo vision algorithm was applied to compute the 3D coordinates of node points. Finally, the kinematics equation of the three-axis parallel manipulator was established, and the three-dimensional coordinates of the nodes were transformed into the corresponding parameters X, Y, and Z of the three driving sliders of the manipulator. The experimental results indicated that the automatic vision system had a success rate of 98.4%, 0.68 s time consumed per 3 plants, and approximate 1 mm location error in locating the plantlets in an appropriate position for the medial expansion period (22 days).

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Demma, A., P. Cawley, M. Lowe, and B. Pavlakovic. "The Effect of Bends on the Propagation of Guided Waves in Pipes." Journal of Pressure Vessel Technology 127, no. 3 (2005): 328–35. http://dx.doi.org/10.1115/1.1990211.

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The practical testing of pipes in a pipe network has shown that there are issues concerning the propagation of ultrasonic guided waves through bends. It is therefore desirable to improve the understanding of the reflection and transmission characteristics of the bend. First, the dispersion curves for toroidal structures have been calculated using a finite element method, as there is no available analytical solution. Then the factors affecting the transmission and reflection behavior have been identified by studying a straight-curved-straight structure both numerically and experimentally. The frequency dependent transmission behavior obtained is explained in terms of the modes propagating in the straight and curved sections of the pipe.

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29

Kuo, Chi-Wei, and C. Steve Suh. "Dispersion and Attenuation of Guided Waves in Tubular Section with Multi-Layered Viscoelastic Coating — Part II: Circumferential Wave Propagation." International Journal of Applied Mechanics 09, no. 02 (2017): 1750016. http://dx.doi.org/10.1142/s1758825117500168.

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In the second part of the study on guided wave motions in a hollow cylinder with epoxy layers, shear and longitudinal modes propagating in the circumferential direction are investigated. The corresponding dispersion and attenuation characteristic equations are derived by incorporating a complex, frequency-dependent constitutive law for the viscoelastic coating material. Continuous displacement boundary conditions are implemented to model perfect interfacial bonds between the tubular section and applied epoxy coatings. The presence of thin dissipative viscoelastic layers has profound impact on the propagation of both the circumferential shear and longitudinal waves. The number of admissible propagating modes increases with increasing number of viscoelastic layers and higher order modes dissipate significantly less at high frequencies than the lower order modes at low frequencies. Over the frequency range considered, all the circumferential propagating modes are significantly more attenuating than their axial propagating counterparts studied in Part 1 of the paper. Generation of the lowest shear wave mode is suppressed at approximately 0.2 MHz in the coated tubular. However, no such definitive cutoff frequencies are observed for the longitudinal modes regardless of how many viscoelastic layers are considered.

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30

Parashar, Jetendra, and Lalita. "TM mode radiation guiding in an REB-induced plasma duct." Journal of Plasma Physics 55, no. 3 (1996): 387–94. http://dx.doi.org/10.1017/s0022377800018924.

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An intense relativistic electron beam propagating through a plasma creates a low-density plasma duct capable of guiding a free-electron laser mode. The beam dynamics plays an important role in the propagation of TM modes. For (where and are the beam and plasma densities respectively, and a and b are the x and y dimensions of the duct) and beam energy of about 2 MeV, the threshold current turns out to be about 20 kA. For marginal radiation guiding, the size of the plasma duct decreases with beam voltage. Application of a strong DC magnetic field shows that an even narrower duct can guide high-frequency radiation.

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31

Kuo, Chi-Wei, and C. Steve Suh. "On the Dispersion and Attenuation of Guided Waves in Tubular Section with Multi-Layered Viscoelastic Coating — Part I: Axial Wave Propagation." International Journal of Applied Mechanics 09, no. 01 (2017): 1750001. http://dx.doi.org/10.1142/s1758825117500016.

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Guided modes admissible in elastic hollow pipes are derived to establish their dispersion and attenuation characteristics in the presence of multi-layered viscoelastic coatings. Longitudinal waves propagating in the axial direction in response to displacement continuity boundary conditions signifying perfect interfacial bonds are evaluated against a baseline uncoated tubing. Viscoelastic bitumen and epoxy are coating materials applied to improve pipeline reliability. The impact of viscoelastic coating layers on wave dispersion and attenuation are investigated by incorporating complex material properties in the characteristic equation. The real and complex roots of the corresponding characteristic equation are determined, allowing the phase velocity and attenuation dispersion to be depicted as functions of the propagation frequency. The effects of varying attenuation parameter and coating thickness are also examined. Viscoelastic protective materials are found to have a substantial impact on the propagation and attenuation of longitudinal waveguide modes.

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32

Lahaye, T., P. Cren, C. Roos, and D. Guéry-Odelin. "Propagation of guided cold atoms." Communications in Nonlinear Science and Numerical Simulation 8, no. 3-4 (2003): 315–28. http://dx.doi.org/10.1016/s1007-5704(03)00032-7.

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33

Lou, Min, and Stuart Crampin. "Guided‐wave propagation between boreholes." Leading Edge 11, no. 7 (1992): 34–37. http://dx.doi.org/10.1190/1.1436886.

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34

Kim, Seungwan, and Usik Lee. "Effects of Delamination on Guided Waves in a Symmetric Laminated Composite Beam." Mathematical Problems in Engineering 2014 (2014): 1–12. http://dx.doi.org/10.1155/2014/956043.

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For successful structural health monitoring and structural integrity evaluation of a laminated composite structure, it is important to study the effects of delamination on the propagations of the guided waves in a delaminated composite beam by using an accurate and computationally efficient method. Thus, we developed a “frequency-domain” spectral element model for the symmetric composite beams. First-order-shear-deformation-theory (FSDT) based Timoshenko beam theory and Mindlin-Herrmann rod theory are adopted for the flexural (bending) waves and axial (extensional) waves, respectively. A spectral element model is derived from the governing equations of motion by using the variation method in the frequency domain. After validating the accuracy of the proposed spectral element model, the model is used to investigate the effects of delamination on the propagation of guided waves in examples of composite beams.

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Maio, L., V. Memmolo, F. Ricci, ND Boffa, and E. Monaco. "Investigation on fundamental modes of guided waves propagating in symmetric and nonsymmetric composite laminates." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 231, no. 16 (2017): 2988–3000. http://dx.doi.org/10.1177/0954406217698721.

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A quasi-isotropic composite laminate is constructed in an attempt to create a structure that behaves like an isotropic plate. Its membrane behavior is similar to that of the isotropic plate while the bending behavior is quite different from the latter. Moreover, the laminae may or may not be arranged symmetrically with respect to the midplane thereby resulting in a different mechanical response. In this work, guided wave propagation along multiple directions in symmetric and not symmetric quasi-isotropic plates is evaluated. Experimental and numerical results for the fundamental modes A0 and S0 are analyzed for the symmetric and nonsymmetric layups. An eight-node brick type element based on the three-dimensional theory is used in modeling to predict numerically the velocity of wave modes propagating in the graphite/epoxy composite plates. Agreement between experimental and numerical approaches is found and interesting dependencies between velocity of propagating modes and laminate stacking sequence are discussed. A final comparison with analytical dispersion curves obtained by the implementation of the global matrix method is discussed.

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Hayran, Zeki, Seyyed Ali Hassani Gangaraj, and Francesco Monticone. "Topologically protected broadband rerouting of propagating waves around complex objects." Nanophotonics 8, no. 8 (2019): 1371–78. http://dx.doi.org/10.1515/nanoph-2019-0075.

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AbstractAchieving robust propagation and guiding of electromagnetic waves through complex and disordered structures is a major goal of modern photonics research, for both classical and quantum applications. Although the realization of backscattering-free and disorder-immune guided waves has recently become possible through various photonic schemes inspired by topological insulators in condensed matter physics, the interaction between such topologically protected guided waves and free-space propagating waves remains mostly unexplored, especially in the context of scattering systems. Here, we theoretically demonstrate that free-space propagating plane waves can be efficiently coupled into topological one-way surface waves, which can seamlessly flow around sharp corners and electrically large barriers and release their energy back into free space in the form of leaky-wave radiation. We exploit this physical mechanism to realize topologically protected wave-rerouting around an electrically large impenetrable object of complex shape, with transmission efficiency exceeding 90%, over a relatively broad bandwidth. The proposed topological wave-rerouting scheme is based on a stratified structure composed of a topologically nontrivial magnetized plasmonic material coated by a suitable isotropic layer. Our results may open a new avenue in the field of topological photonics and electromagnetics, for applications that require engineered interactions between guided waves and free-space propagating waves, including for complex beam-routing systems and advanced stealth technology. More generally, our work may pave the way for robust defect/damage-immune scattering and radiating systems.

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Shi, Chengzhi, Rongkuo Zhao, Yang Long, et al. "Observation of acoustic spin." National Science Review 6, no. 4 (2019): 707–12. http://dx.doi.org/10.1093/nsr/nwz059.

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ABSTRACT Unlike optical waves, acoustic waves in fluids are described by scalar pressure fields, and therefore are considered spinless. Here, we demonstrate experimentally the existence of spin in acoustics. In the interference of two acoustic waves propagating perpendicularly to each other, we observed the spin angular momentum in free space as a result of the rotation of local particle velocity. We successfully measured the acoustic spin, and spin-induced torque acting on a designed lossy acoustic probe that results from absorption of the spin angular momentum. The acoustic spin is also observed in the evanescent field of a guided mode traveling along a metamaterial waveguide. We found spin–momentum locking in acoustic waves whose propagation direction is determined by the sign of spin. The observed acoustic spin could open a new door in acoustics and its applications for the control of wave propagation and particle rotation.

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38

Kwan, P., and C. Vittoria. "Propagation characteristic of a ferrite image guide." Journal of Applied Physics 73, no. 10 (1993): 6466–68. http://dx.doi.org/10.1063/1.352581.

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Arambepola, S. L., and J. R. Cozens. "Propagation in a doubly periodic dielectric guide." IEE Proceedings J Optoelectronics 133, no. 5 (1986): 332. http://dx.doi.org/10.1049/ip-j.1986.0057.

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Yuan, Maodan, Peter W. Tse, Weiming Xuan, and Wenjin Xu. "Extraction of Least-Dispersive Ultrasonic Guided Wave Mode in Rail Track Based on Floquet-Bloch Theory." Shock and Vibration 2021 (February 8, 2021): 1–10. http://dx.doi.org/10.1155/2021/6685450.

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Ultrasonic guided wave (UGW) has shown great potential in the field of structural health monitoring of rail tracks due to its long-range capability and full cross section coverage. However, the practical application of UGW has been hindered by the complicated signal interpretation because of the natures of multiple modes and dispersion. Therefore, it is desirable that the effective UGW modes with high excitability and least dispersion can be identified and extracted for practical applications. In this paper, a numerical study on the guided wave propagation was carried out on a standard rail with 56E1 profile. Firstly, Floquet-Bloch theory was applied to obtain the dispersion curves of guided wave in a rail. Then, a 3D FE model was built to investigate the UGW propagation along the rail within the frequency range of 0–120 kHz. Wavenumber-frequency analysis method was applied to decompose and identify the propagating UGW modes. With a carefully designed 2D bandpass filter, a specific mode W0 was extracted in the wavenumber-frequency domain. Finally, a frequency band sweep technique was also proposed to get the optimal frequency band to achieve a pure and least-dispersive UGW mode along the rail web. The proposed method provides an effective way to extract efficient UGW modes to assess the integrity of the rail track, as well as other waveguides with complex geometry.

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Wang, Ying, and Hong Hao. "Modelling of Guided Wave Propagation with Spectral Element: Application in Structural Engineering." Applied Mechanics and Materials 553 (May 2014): 687–92. http://dx.doi.org/10.4028/www.scientific.net/amm.553.687.

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Among many structural health monitoring (SHM) methods, guided wave (GW) based method has been found as an effective and efficient way to detect incipient damages. In comparison with other widely used SHM methods, it can propagate in a relatively long range and be sensitive to small damages. Proper use of this technique requires good knowledge of the effects of damage on the wave characteristics. This needs accurate and computationally efficient modeling of guide wave propagation in structures. A number of different numerical computational techniques have been developed for the analysis of wave propagation in a structure. Among them, Spectral Element Method (SEM) has been proposed as an efficient simulation technique. This paper will focus on the application of GW method and SEM in structural health monitoring. The GW experiments on several typical structures will be introduced first. Then, the modeling techniques by using SEM are discussed.

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OKAMURA, Yasuyuki. "Evaluation of Guided-Wave Propagation Characteristics." Review of Laser Engineering 19, no. 4 (1991): 305–15. http://dx.doi.org/10.2184/lsj.19.4_305.

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Tan, Xiao, Changming Sun, Kwan-Yee K. Wong, and Tuan D. Pham. "Guided image completion by confidence propagation." Pattern Recognition 50 (February 2016): 210–22. http://dx.doi.org/10.1016/j.patcog.2015.08.003.

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Xia, J., S. W. McKnight, and C. Vittoria. "Propagation losses in dielectric image guides." IEEE Transactions on Microwave Theory and Techniques 36, no. 1 (1988): 155–58. http://dx.doi.org/10.1109/22.3498.

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Cottis, P. G. "Propagation in eccentrically cladded anisotropic guides." IEE Proceedings J Optoelectronics 140, no. 2 (1993): 119. http://dx.doi.org/10.1049/ip-j.1993.0021.

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He, Kuanfang, Zhi Tan, Yong Cheng, and Xuejun Li. "Acoustic emission propagation characteristics in plate structure with various materials, cracks and coating metal." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 231, no. 11 (2016): 2080–88. http://dx.doi.org/10.1177/0954406215627822.

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The propagation characteristic of guided waves is important to acoustic emission nondestructive detection for the structural integrity of engineering components. The finite element method is introduced to study the propagation of guided waves in plate structure with different materials, cracks and coating metal. The displacement contours and wave curve at different receiving positions are examined first for the propagation characteristics of guided waves in plate structure with different homogeneous material of steel 45 and GCr15. Next, the interface reflection, refraction and diffraction characteristics of guided waves in plate structure with cracks and steel 45 with coating metal of aluminium 2024 are investigated. Finally, these FE results are compared with the mechanical pencil lead fracture experiment results. The results of this study clearly illustrate the accuracy and reasonableness of the finite element method to predict propagation characteristic of guided wave.

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Kodama, Y., and A. Hasegawa. "Nonlinear pulse propagation in a monomode dielectric guide." IEEE Journal of Quantum Electronics 23, no. 5 (1987): 510–24. http://dx.doi.org/10.1109/jqe.1987.1073392.

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48

Cory, H., and T. Blum. "Surface-wave propagation along a metamaterial cylindrical guide." Microwave and Optical Technology Letters 44, no. 1 (2004): 31–35. http://dx.doi.org/10.1002/mop.20538.

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Rao, K. Mrithyumjaya. "Longitudinal wave propagation in a micropolar wave guide." International Journal of Engineering Science 26, no. 2 (1988): 135–41. http://dx.doi.org/10.1016/0020-7225(88)90100-0.

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50

Hu, Chaoyue, Jiang Xu, and Yunfei Li. "Feasibility study of detecting the end contacting status of threaded-sleeve-connected reinforcing bar using magnetostrictive guided wave." International Journal of Applied Electromagnetics and Mechanics 64, no. 1-4 (2020): 557–64. http://dx.doi.org/10.3233/jae-209364.

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The reinforcing bar connected by threaded sleeve is widely used. The end contacting status under the sleeve indicates the tightness of the threaded sleeve connection. In this paper, the feasibility of using magnetostrictive guided wave to detect the end contacting status of the reinforcing bar is studied. Firstly, the propagation characteristic of the wave propagating through the threaded sleeve connection is analyzed. The end contacting status affects the reflection and transmission of the wave. Then, experiments are carried out on a thread-sleeve-connected reinforcing bar. The passing signals of the threaded sleeve connection at an exciting frequency of 30 kHz can be used to distinguish end contacting status of the reinforcing bar. Additionally, the peak voltage of the passing signal’s first passing wave decreases with the increasing loosening angle of the threaded sleeve connection. The study proves the feasibility of detecting the end contacting status using magnetostrictive guided wave.

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