The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Yinhui Zou - One of the best experts on this subject based on the ideXlab platform.
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A Novel Study of Waveguide Propagation Rules of Coal Rock AE Signal: Effects of Waveguide Size and Installation Method on the Propagation Rules of Coal Rock AE Signal
Sustainability, 2017Co-Authors: Guowei Dong, Yinhui ZouAbstract:The propagation of acoustic emission (AE) signal in waveguide is quite important for AE-based prediction of dynamic disasters in coal rocks. In this study, based on some relevant theories in wave mechanics, the elastic mechanical model of one-dimensional (1D) waveguide was firstly established, and the relationship between AE source signal and the signal at the waveguide’s receiving end was derived. On the basis of theoretical analysis, numerical simulation and laboratory test schemes were designed; additionally, using the standard vibration source method, AE response in different sizes of Waveguides were investigated, the effects of waveguide size of waveguide were concluded, and the application conditions of the established theoretical model were clarified. Numerical simulation results fit well with the laboratory test results. Meanwhile, the effects of the sensor’s installation method on the propagation rules of AE signal were examined and appropriate installation method was determined.
Pierre A Deymier - One of the best experts on this subject based on the ideXlab platform.
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tunable filtering and demultiplexing in phononic crystals with hollow cylinders
Physical Review E, 2004Co-Authors: Yan Pennec, B Djafarirouhani, J O Vasseur, Abdelkrim Khelif, Pierre A DeymierAbstract:tunable narrow pass band ~NPB! located inside their gap. We theoretically investigate, using the finite difference time domain ~FDTD! method, the properties of Waveguides composed of a row of hollow cylinders in a two-dimensional ~2D! phononic crystal made of filled steel cylinders. These Waveguides exhibit NPB’s at frequencies slightly higher than their infinite periodic ABG counterpart. The frequency of the waveguide’s NPB can be selected by adjusting the inner radius of the hollow cylinders or by changing the nature of the fluid that fills them. We show that a waveguide constituted of a row of hollow cylinders with different inner radii can transport waves at two different frequencies. By selectively filling the cylinders with water or mercury we have created an active device that permits the transmission of waves at one, both, or neither of these frequencies. Finally, we examine the multiplexing and demultiplexing capabilities of Y shaped Waveguides constituted of hollow cylinders.
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Tunable filtering and demultiplexing in phononic crystals with hollow cylinders.
Physical Review E, 2004Co-Authors: Yan Pennec, J O Vasseur, Abdelkrim Khelif, Bahram Djafari-rouhani, Pierre A DeymierAbstract:Acoustic band gap (ABG) materials constituted of steel hollow cylinders immersed in water can exhibit a tunable narrow pass band (NPB) located inside their gap. We theoretically investigate, using the finite difference time domain (FDTD) method, the properties of Waveguides composed of a row of hollow cylinders in a two-dimensional (2D) phononic crystal made of filled steel cylinders. These Waveguides exhibit NPB's at frequencies slightly higher than their infinite periodic ABG counterpart. The frequency of the waveguide's NPB can be selected by adjusting the inner radius of the hollow cylinders or by changing the nature of the fluid that fills them. We show that a waveguide constituted of a row of hollow cylinders with different inner radii can transport waves at two different frequencies. By selectively filling the cylinders with water or mercury we have created an active device that permits the transmission of waves at one, both, or neither of these frequencies. Finally, we examine the multiplexing and demultiplexing capabilities of Y shaped Waveguides constituted of hollow cylinders.
Guowei Dong - One of the best experts on this subject based on the ideXlab platform.
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A Novel Study of Waveguide Propagation Rules of Coal Rock AE Signal: Effects of Waveguide Size and Installation Method on the Propagation Rules of Coal Rock AE Signal
Sustainability, 2017Co-Authors: Guowei Dong, Yinhui ZouAbstract:The propagation of acoustic emission (AE) signal in waveguide is quite important for AE-based prediction of dynamic disasters in coal rocks. In this study, based on some relevant theories in wave mechanics, the elastic mechanical model of one-dimensional (1D) waveguide was firstly established, and the relationship between AE source signal and the signal at the waveguide’s receiving end was derived. On the basis of theoretical analysis, numerical simulation and laboratory test schemes were designed; additionally, using the standard vibration source method, AE response in different sizes of Waveguides were investigated, the effects of waveguide size of waveguide were concluded, and the application conditions of the established theoretical model were clarified. Numerical simulation results fit well with the laboratory test results. Meanwhile, the effects of the sensor’s installation method on the propagation rules of AE signal were examined and appropriate installation method was determined.
Guo-qiang Lo - One of the best experts on this subject based on the ideXlab platform.
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New design and analysis of Bragg grating Waveguides.
Optics Express, 2010Co-Authors: Kensuke Ogawa, Ning Guan, Ken Sakuma, Mingbin Yu, Guo-qiang LoAbstract:New design of optical Waveguides is presented to synthesize Bragg grating Waveguides without inducing birefringence. In the design, waveguide core has a thin trench on the top surface of the core and width of the trench is modulated concurrently with width modulation of the waveguide core. Effective refractive index profiles in Bragg grating Waveguides are obtained by a differential inverse scattering algorithm and converted to waveguide width profiles by using the new core design. This procedure allows design of non-birefringent Bragg grating Waveguides on planar substrate. The method is applied to the design of chromatic dispersion compensators. For characterization of Bragg grating Waveguides, analysis based on short-time Fourier transform of Bragg grating response waveforms is presented.
Heping Zhao - One of the best experts on this subject based on the ideXlab platform.
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One-way transmission and mode conversion of elastic waves by a hybrid phononic crystal structure
Journal of Applied Physics, 2019Co-Authors: Ji-en Wu, Ruixia Hu, Bing Tang, Xiao-yun Wang, Ke Deng, Zhaojian He, Heping ZhaoAbstract:We study the one-way transmission and mode conversion of elastic waves by a hybrid phononic-crystal structure that consists of two mutually perpendicular phononic-crystal Waveguides connected by a resonant cavity. Based on the mode matching mechanism between the cavity and Waveguides, the symmetrical waves incident on the waveguide entrance are converted into antisymmetric modes and exit the waveguide. However, for the same waves incident on the structure from the waveguide exit, no output waves are transmitted toward the waveguide entrance because the modes in the Waveguides and the cavity are mismatched. On the basis of this unique property, we designed a polarization-sensitive composite structure to measure the angle between two components of incident mixed elastic waves.We study the one-way transmission and mode conversion of elastic waves by a hybrid phononic-crystal structure that consists of two mutually perpendicular phononic-crystal Waveguides connected by a resonant cavity. Based on the mode matching mechanism between the cavity and Waveguides, the symmetrical waves incident on the waveguide entrance are converted into antisymmetric modes and exit the waveguide. However, for the same waves incident on the structure from the waveguide exit, no output waves are transmitted toward the waveguide entrance because the modes in the Waveguides and the cavity are mismatched. On the basis of this unique property, we designed a polarization-sensitive composite structure to measure the angle between two components of incident mixed elastic waves.
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one way transmission and mode conversion of elastic waves by a hybrid phononic crystal structure
Journal of Applied Physics, 2019Co-Authors: Bing Tang, Xiao-yun Wang, Ke Deng, Han Jia, Heping ZhaoAbstract:We study the one-way transmission and mode conversion of elastic waves by a hybrid phononic-crystal structure that consists of two mutually perpendicular phononic-crystal Waveguides connected by a resonant cavity. Based on the mode matching mechanism between the cavity and Waveguides, the symmetrical waves incident on the waveguide entrance are converted into antisymmetric modes and exit the waveguide. However, for the same waves incident on the structure from the waveguide exit, no output waves are transmitted toward the waveguide entrance because the modes in the Waveguides and the cavity are mismatched. On the basis of this unique property, we designed a polarization-sensitive composite structure to measure the angle between two components of incident mixed elastic waves.
