R. Costley, H. Diaz-Alvarez, M. McKenna, A. Miller
U.S. Army Engineer Research and Development Center, Vicksburg, MS, USA
Two finite element models have been developed to investigate the acoustic radiation from a Pratt truss train bridge. The first model was a time dependent structural model that determined the vibration response of the structure due to two wheels, representing a single axle, moving across the bridge at constant speed. This model was expanded to include multiple axles to represent a locomotive. The ...
F. Botta, D. Dini, S. Gentili, G. Cerri
Dipartimento di Ingegneria Meccanica e Industriale, Università degli Studi di Roma Tre, Roma, Italy
Department of Mechanical Engineering, Imperial College London, London, United Kingdom
Turbomachines blades are forced by a load resulting from the interaction with the fluid. The consequent vibrations, and the associated fatigue phenomena, can give catastrophic failures and the reduction of the blades life. It could be increased if damping system are used. The piezoelectric materials has received considerable attention by many researcher for their potential application in the ...
G. Vigna, L. Spicci
Esaote SPA, Florence, Italy
Self-heating is a problem to consider for Ultrasound Imaging probes. Since the probe is in contact with the skin, it’s necessary to find a solution to lower the front face temperature in order to avoid patient discomfort, even at the most demanding operating condition. One solution consists in the design of a device that drains the heat from the front to the rear of the transducer, where a ...
DepQuest, Dalmine, Italy
This work focuses on the application of multiphysics finite element simulations in the manufacturing and application of high power ultrasonic machines. Industries providing big power ultrasonic solutions as in cleaning, welding, sonochemistry and cutting fields, already apply the finite element simulation approach, in the structural mechanics flavor, in the design and optimization of ultrasonic ...
K. McIlhany, and R. Malek-Madani
Physics Department, United States Naval Academy, Annapolis, MD, USA
Mathematics Department, United States Naval Academy, Annapolis, MD, USA
In 1966, mathematician Mark Kac proposed the question "Can One Hear the Shape of a Drum?" in an article for American Mathematical Monthly. In attempting to resolve the Chesapeake Bay from an eigenfunctional approach, a one-to-one mapping of this famous problem has been identified. The quote above will re-write to "Can One Hear the Shape of a Drum from Multiple Point-Sampled Spectra?". This ...
M. Quinn, D. Whitlow, O.D.S. Taylor, M.H. McKenna
 Engineer Resource and Development Center, United States Army Corps of Engineers, Vicksburg, MS, USA
Bridge piers and abutments makeup the bridge substructure and transmit loads from the superstructure to the bridge foundation material (Figure 1). The bridge abutment serves three purposes: to provide vertical support to the bridge superstructure where the bridge ends, to connect the bridge with the approach roadway, and to retain roadway base materials. There are several types of abutment ...
B. Baumann, M. Wolff, J. Hirsch, P. Antonis, S. Bhosle, and R. Valdivia Barrientos
Hamburg University of Applied Sciences, Hamburg, Germany
Philips Lighting, Eindhoven, The Netherlands
LAPLACE, Université de Toulouse and CNRS, Toulouse, France
National Institute of Nuclear Research, Salazar, Ocoyoacac, Mexico
High intensity discharge lamps can experience flickering and even destruction, when operated at high frequency alternating current. The cause of these problems has been identified as acoustic resonances inside the lamp’s are tube. Here, a finite element approach for the calculation of the acoustic response function is described. The developed model does not include the plasma dynamics.
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 ...
Modeling of Ultrasonic Transducers and Ultrasonic Wave Propagation for Commercial Applications Using Finite Elements with Experimental Visualization of Waves for Validation - new
D. R. Andrews
Cambridge Ultrasonics, Over, UK
Finite element (FE) modelling of ultrasonic propagation using COMSOL Multiphysics® simulations can be used to create images of waves. Unfortunately, in time-stepping solutions, it is possible for numerical instabilities to grow large and dominate the solution adversely. Any design of transducer that is based upon poorly-configured FE models is unlikely to perform as expected and will almost ...
Mitsubishi Turbocharger & Engine Europe, Almere, The Netherlands
This study presents a rotordynamic analysis of a rotor on hydrodynamic bearings using COMSOL Multiphysics®. In this paper, the complexity of the model is gradually increased. Starting point of the analysis is the modal analysis of the rotor in free-free conditions. A Reynolds model is set up to predict the film pressure distribution under shaft loading. Due to the cross coupling terms of the ...