T. H. Hanley, H. T. D. Grigg, B. J. Gallacher
Newcastle University, Newcastle-Upon-Tyne, UK
Introducing a disorder into a finite periodic oscillatory system induces the presence of a 'trapped mode': a mode in which the displacement field is localised to the region of the disorder. A main inhibitor to MEMS resonators achieving a high quality (Q) factor is energy radiation through the support to the substrate. The trapped modes present a way to tune this to a minimal value. An initial ...
W. R. Kampinga, and Y. H. Wijnant
Reden, Hengelo, Netherlands
University of Twente, Enschede, Netherlands
Three efficient alternatives to the model in COMSOL’s thermoacoustics interface are presented. The higher efficiency of these models are explained from theory and are demonstrated by means of two examples.
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.
S. De Paolis, F. Lionetto, and A. Maffezzoli
Department of Innovation Engineering, University of Salento, Lecce, Italy
Finite element analysis has been used to model the ultrasonic wave propagation both in a custom made transducer and in the tested polymer sample. The model consists of acoustic (passive elements) and electroacoustic (active elements) transmission lines. The simulation of the acoustic propagation accounts for the interaction between the transducer and the materials in the buffer rods, and the ...
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. ...
Simulation of Helmholtz Resonators for Optical Gas Sensing: Comparison Between Pressure Acoustics and Thermoacoustics - new
B. Parvitte, C. Risser, R. Vallon, V. Zéninari
Université de Reims, Reims, France
Among optical gas sensing methods, photoacoustic (PA) spectroscopy combined with a laser source has proven to be a very robust and sensitive method for trace gas detection. COMSOL Multiphysics® software was used to calculate the frequency response of differential Helmholtz resonator cells in order to optimize the detection limit of PA sensors. Two different kind of simulation were performed: ...
S.L. Firebaugh, F. Roignant, and E.A. Terray
United States Naval Academy, Annapolis, Maryland, USA
Polytechnique Nantes, Nantes, France
Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
A fast, high-sensitivity detector is required for studies of environmentally relevant gases. Photoacoustic spectroscopy (PAS), an absorption spectroscopy technique in which absorption is detected as sound, is explored as a possible solution. A tuning-fork based PAS sensor is modeled using COMSOL. The model combines the acoustic and piezoelectric modules and also includes viscous damping. The ...
N. Chowdhury, Z. Liao, and L. Zhao
Department of Electrical & Computer Engineering, Ryerson University, Toronto, ON, Canada
Department of Architectural Science, Ryerson University, Toronto, ON, Canada
Acoustic wave propagation due to the breakage or slippage of reinforced wire in water-filled prestressed concrete cylinder pipe (PCCP) attracts interest in non-destructive pipe testing. Current practice of acoustic emission (AE) detection and wire-break related events (WRE) recognition is based on field data analysis. This work deals with the theoretical investigation of WRE signal from ...
J. McKenna, M. McKenna, S. Yushanov, J. Crompton, and K. Koppenhoefer
U.S. Army Engineering Research and Development Center
ACES of Columbus, LLC, Columbus, OH, USA
The propagation of shear (S) and compression (P) waves within the earth allows geologists to track seismic events and to identify subterranean structure. This work shows the strong effect of including the variation of wave speed through the top thirty meters of the earth. By including this variation in material properties, the wave arrival time and frequency content agree with experimental data. ...
C. Yang, M. A. Torres-Arredondo, and C.-P. Fritzen
Institute of Mechanics and Control Engineering
University of Siegen
Impact monitoring has been extensively studied by several researchers and it has been shown that damage extent can be correlated with the impact magnitude. In order to make the process cost-effective, simulation of the impact has been performed, to get the big training data set from modeling. The structural dynamic responses captured by PZT transducers due to impact events are recorded from ...