Lamb Waves and Dispersion Curves in Plates and It’s Applications in NDE Experiences Using Comsol Multiphysics
P. Gómez, J. P. Fernandez, and P. D. García
Hydro-Geophysics & NDE Modeling Unit
University of Oviedo
In this paper, a model for numerically obtaining lamb wave modes and dispersion curves in plates is presented. It is shown that COMSOL Multiphysics can be employed to simulate the behavior of guided waves in dispersive plates, which is useful for NDE applications. A two dimensional steel plate (4x0.1 meters) is excited with a space-time impact point source. To model the point source, we use ...
Tohoku Institute of Technology
This paper is in Japanese.
J. Muraoka, and T. Suzuki
Yamagata Research Institute of Technology
The traveling wave ultrasonic vibration disks for dispersion of particles were designed by using of FEM analysis. The vibration disks are required specific vibration pattern, which contains three nodal lines. The vibration disk thickness was calculated to be matched the resonance frequency of bolted langevin type transducer and the specific vibration pattern. The alignment of the transducer was ...
Simulation Analysis of Acoustic Radiation Force under Ultrasound Exposure and Effect to Microbubbles in Flow
Tokyo University of Agriculture & Technology
This paper is in Japanese.
H. Bruus, P.B. Muller, R. Barnkob, M.J.H. Jensen
Technical University of Denmark, Kongens Lyngby, Denmark
COMSOL, Kongens Lyngby, Denmark
We have simulated the ultrasound-induced acoustophoretic motion of microparticles suspended in an aqueous solution. The full first-order thermoviscous acoustics equations have been implented on a rectangular microfluidic 2D domain excited with an ultrasound field tuned to resonance near 2 MHz. The micrometer-thin but crucial viscous boundary layers at the rigid walls have been fully resolved. The ...
L.B.M. Silva, E.J.P. Santos
Laboratory for Devices and Nanostructures, Electronics and Systems Department, Universidade Federal de Pernambuco, Recife, PE, Brasil
Transducer optimization is a key aspect for successful development and deployment of advanced sensors, especially when designing 3D structures for harsh environments. For piezoelectric transducers, plate thickness determines the operating frequency of the resonator, which is frequently tuned in the shear thickness vibration mode. Quartz has been the material of choice for the fabrication of bulk ...
M. Usai, S. Carcangiu, G. Concu
Department of Electrical and Electronic Engineering, University of Cagliari, Cagliari, Italy
Department of Civil Engineering, Environmental and Architecture, University of Cagliari, Cagliari, Italy
In the field of assessment methodologies, particular importance is given to Non-Destructive Testing Techniques, which aspire to achieve the highest number of information about materials and structures without altering their condition. Ultrasonic Testing exploits the transmission and reflection characteristics of mechanical waves with appropriate frequencies passing through the investigated item. ...
Glass Plates Noise Transmission Suppression by Means of Distributed Piezoelectric Composite Actuators Shunted by an Active Circuit
K. Novakova, P. Mokry
Research Centre for Special Optics and Optoelectronic Systems (TOPTEC), Institute of Plasma Physics, Academy of Sciences of the Czech Republic, Turnov, Czech Republic
Institute of Mechatronics and Computer Engineering, Technical University of Liberec, Liberec, Czech Republic
Glass windows represent a virtual sound source for buildings interior. It is very easy to make them vibrate by action of incident acoustic pressure wave. Therefore, non-negligible part of the wave is transmitted through the window. We propose and simulate a method based on the change of mechanical properties of the plate using flexible piezoelectric Macro Fiber Composite actuators distributed on ...
R. Sisto, L. Cerini, D. Mambro, A. Moleti, F. Sanjust
INAIL Research, Monteporzio Catone, Italy
Università di Roma, Tor Vergata, Italy
The otoacoustic emissions (OAEs) are acoustic signals emitted by the inner ear as a consequence of the activity of a nonlinear feedback mechanism capable of amplifying the signal near to the hearing threshold level. The otoacoustic emissions can be used as an acoustic imaging of the cochlear functionality. They are used in clinics for screening purposes but due to the extreme variability between ...
Y.F. Wang, Y.S. Wang, L. Wang
Institute of Engineering Mechanics, Beijing Jiaotong University, Beijing, China
Department of Mechanical Engineering, Østfold University College, Halden, Norway
We show in this paper that by careful design of the geometry of the resonators, complete bandgap with relatively low center frequency can be obtained for 2D and 3D Phononic Crystals with resonators. The generation of the bandgap is due to the local resonance of the unit cell. Spring-mass and spring-pendulum models are developed to predict the boundaries of the complete bandgap. The predicted ...