The Experts below are selected from a list of 55518 Experts worldwide ranked by ideXlab platform
Yuanwen Gao - One of the best experts on this subject based on the ideXlab platform.
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tunability of Longitudinal Wave band gaps in one dimensional phononic crystal with magnetostrictive material
Journal of Applied Physics, 2014Co-Authors: Rui Ding, Juanjuan Zhang, Yuanwen GaoAbstract:Ways for controlling and adjusting the Longitudinal Wave band structures of one dimensional (1-D) rod phononic crystals with magnetostrictive material are theoretically investigated by the plane Wave expansion method. Z-L model is adopted to accurately describe the constitutive relations of phononic crystal containing magnetostrictive material. Taking the magneto-mechanical coupling into account, the Longitudinal Wave band structures are calculated through the development of effective elastic constant, piezomagnetic constant, and magnetic permeability for magnetostrictive rod. Numerical results show that the Longitudinal Wave band gaps characteristics are significantly influenced by the applied static magnetic field and compressive pre-stress. Some new phenomena, such as the multi-peaks of the band gap widths corresponding to the varying filling fraction of the binary rod phononic crystal, are investigated.
Ilia Katardjiev - One of the best experts on this subject based on the ideXlab platform.
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quasistatic transduction of the fundamental symmetric lamb mode in Longitudinal Wave transducers
Applied Physics Letters, 2006Co-Authors: Ventsislav Yantchev, Ilia KatardjievAbstract:The Green’s function formalism has been applied to the analysis of the fundamental symmetric Lamb mode excited by means of Longitudinal Wave (LW) transducers. The Lamb Wave Green’s function has been related to the properties of the effective permittivity defined as a function of the Wave slowness and the relative plate thickness. An electrostatic analysis that neglects the piezoelectric coupling is employed to relate the charge density to the applied voltage. This analysis is subsequently used to calculate the radiation conductance of a LW transducer. The results obtained are consistent with the equivalent circuit approach and define the device coupling as a function of the plate thickness and the intrinsic Lamb Wave coupling.
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design and fabrication of thin film lamb Wave resonators utilizing Longitudinal Wave and interdigital transducers
Internaltional Ultrasonics Symposium, 2005Co-Authors: Ventsislav Yantchev, Ilia KatardjievAbstract:Design and Fabrication of thin film Lamb Wave Resonators utilizing Longitudinal Wave and Interdigital Transducers
Nicolas Favrie - One of the best experts on this subject based on the ideXlab platform.
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Modeling Longitudinal Wave propagation in nonlinear viscoelastic solids with softening
International Journal of Solids and Structures, 2018Co-Authors: Harold Berjamin, Bruno Lombard, Guillaume Chiavassa, Nicolas FavrieAbstract:A model for Longitudinal Wave propagation in rocks and concrete is presented. Such materials are known to soften under a dynamic loading, i.e. the speed of sound diminishes with forcing amplitudes. Also known as slow dynamics, the softening of the material is not instantaneous. Based on continuum mechanics with internal variables of state, a new formulation is proposed, which accounts for nonlinear Zener viscoelasticity and softening. A finite-volume method using Roe linearization is developed for the system of partial differential equations so-obtained. The method is used to carry out resonance simulations, and its performance is assessed in the linear viscoelastic case. Qualitative agreement with experimental results of nonlinear ultrasound spectroscopy (NRUS) and dynamic acousto-elastic testing (DAET) is obtained.
Akira Nagano - One of the best experts on this subject based on the ideXlab platform.
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distribution of Longitudinal Wave properties in bovine cortical bone in vitro
Ultrasonics, 2006Co-Authors: Yu Yamato, Mami Matsukawa, Kaoru Yamazaki, Takahiko Otani, Akira NaganoAbstract:The detailed spatial distributions of Longitudinal ultrasonic velocity in cortical bone specimens obtained from three bovine femoral diaphysis were experimentally investigated using a pulse-echo system. The relationship between velocity, density, bone mineral density (BMD) and microstructure was investigated. Velocity was found to vary as a function of the direction of propagation and the location of the measured specimens in the bone diaphysis. A significant correlation was found between density and velocity, and between density and BMD. In some parts with plexiform structure, clear variations in velocity anisotropy were found despite no significant difference in density, BMD and microstructure.
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distribution of Longitudinal Wave velocities in bovine cortical bone in vitro
Japanese Journal of Applied Physics, 2005Co-Authors: Yu Yamato, Mami Matsukawa, Hideo Kataoka, Kaoru Yamazaki, Takahiko Otani, Akira NaganoAbstract:The distribution of Longitudinal Wave velocities and Longitudinal moduli in a bovine femoral cortical bone was experimentally investigated. In all parts of the long cylindrical bone, the velocities and Longitudinal moduli in the axial direction were the highest. In the anterior (A) part, the velocities in the axial direction were high and almost constant, whereas the velocities in the proximal postero medial (PM) and distal postero lateral (PL) parts markedly decreased. Classifying the cortical bone into three structures (plexiform, Haversian, and porotic), we clarify the velocity distributions in the bone with discussion from an anatomical point of view.
Gerard Gary - One of the best experts on this subject based on the ideXlab platform.
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a three dimensional analytical solution of the Longitudinal Wave propagation in an infinite linear viscoelastic cylindrical bar application to experimental techniques
Journal of The Mechanics and Physics of Solids, 1995Co-Authors: Han Zhao, Gerard GaryAbstract:This paper presents an original three dimensional (3D) analytical general solution of the Longitudinal Wave propagation in an infinite linear viscoelastic cylindrical bar and its applications to some experimental methods of material behaviour testing to improve their accuracy. One application is to take into account the Wave dispersion effects in the split Hopkinson pressure bar (SHPB) setup composed of viscoelastic bars. Another is to eliminate the geometrical effects in an impulse test in which the linear viscoelastic material properties can be deduced from the change in the Wave shape due to the propagation between two points of measurement in a specimen bar.
