Presentazioni e Articoli Tecnici

In questa sezione troverete i lavori presentati alle Conferenze mondiali COMSOL. Le presentazioni descrivono ricerche e prodotti innovativi progettati con COMSOL Multiphysics da colleghi di tutto il mondo. I temi delle ricerche presentate abbracciano un'ampia gamma di settori produttivi e aree applicative, in ambito elettrico, meccanico, fluidodinamico e chimico. Lo strumento di Ricerca Rapida vi permetterà di trovare le presentazioni che si riferiscono all'area di vostro interesse.

Nondestructive Testing of Composites Using Model Based Design

E. Nesvijski[1]

There is a practical interest among composite materials manufacturers to high-speed accurate non-destructive evaluation (NDE) technology for voids inspection when these voids are natural components of such complex structures like resin insulated layer of double-sided copper-clad laminates. Model based design (MBD) of NDE system is one of principal solutions for voids inspection in such composites ...

Ultrasound Propagation in Viscoelastic Material Guides

Castaings, M.1, Predoi, M.V.2, Hosten, B.1 1 Laboratoire Mécanique Physique, Univ. Bordeaux 1, UMR CNRS 5469, Talence, France
2 Catedra de Mecanica, Universitatea Politehnica Bucuresti, Bucuresti, Romania

Wave propagation in elastic waveguides is a problem of constant interest from the last decades. Several numerical approaches exist. The most intuitive uses time-marching routines that solve the equations of dynamic equilibrium and supply displacements of the structure nodes as time functions. This procedure is usually time and memory consuming due to huge number of temporal iterations required ...

Acoustic Transparency of Non-homogeneous Plates (with repeating inclusions) using Periodic Structures Methodology

A. J. Kalinowski
Naval Undersea Warfare Center/Div. Npt. Newport, RI, USA

The paper addresses a class of problems for determining the acoustic interaction of time-harmonic plane waves impinging upon submerged elastic plates (fluid backed or void backed), that are infinite in extent.The plates can have repeated equally spaced inclusions (voids, solids, ribs etc.), and also can be constructed from orthotropic and/or isotropic layers that can have a frequency dependent ...

Acoustic Emission Simulation for Online Impact Detection

C. Yang, M. A. Torres-Arredondo, and C.-P. Fritzen
Institute of Mechanics and Control Engineering
University of Siegen
Siegen, Germany

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 ...

Simulation of a Piezoelectric Loudspeaker for Hearing Aids and Experimental Validation - new

G. C. Martins[1], P. R. Nunes[1], J. A. Cordioli[1]
[1]Federal University of Santa Catarina, Florianópolis, SC, Brazil

The use of piezoelectric materials in hearing aid loudspeakers, also called receivers, presents technical and economic advantages such as reducing the number of parts of the system and its manufacturing cost. However, the performance of such systems is still not competitive when compared to traditional electrodynamic loudspeakers. In order to achieve an appropriate performance, one option is to ...

Modeling the response of photoacoustic gas sensors

S.L. Firebaugh[1], F. Roignant[2], and E.A. Terray[3]

[1]United States Naval Academy, Annapolis, Maryland, USA
[2]Polytechnique Nantes, Nantes, France
[3]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 ...

Numerical Shape Optimization of Photoacoustic Sample Cells: First Results

B. Baumann1, B. Kost1, M. Wolff1,2, H. Groninga2, T. Blöß1, and S. Knickrehm1
1Hamburg University of Applied Sciences, Hamburg, Germany
2PAS-Tech GmbH, Zarrentin, Germany

First results in the automatic shape optimization of a photoacoustic sample cell are described. The aim is to maximize the sensor’s signal strength. The approach considers all shapes that can be represented by a number of axis-symmetrical truncated cones which are connected in a continuous way. In addition, the cell is subjected to certain constraints (e.g. the laser beam is not blocked during ...

Linear Water Wave Propagation around Structures

L. Martinelli, and A. Lamberti
Universita di Bologna, Italy

Objective of this contribution is to show how to implement the Mild Slope Equations with COMSOL Multiphysics. These equations are commonly used to study the propagation of waves in harbors. Some interesting features are presented, namely the use of weak terms (used for the modelling of the source term); the evaluation of a smooth phase gradient from the complex dependent variable; a robust ...

FEM Simulation of Generation of Bulk Acoustic Waves and their Effects in SAW Devices

A.K. Namdeo[1], N. Ramakrishnan[2], and H.B. Nemade[1]
[1]Department of Electronics and Communication Engineering, Indian Institute of Technology Guwahati, Guwahati, India
[2]Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati, India

This paper presents finite element method (FEM) simulation study of the generation of bulk acoustic waves (BAWs) and their effect on the performance of surface acoustic wave (SAW) devices, using COMSOL Multiphysics. A SAW delay line structure using YZ-cut lithium niobate substrate is simulated. The radiation of the bulk waves in all angles into the interior of the substrate is analyzed. The bulk ...

Using COMSOL to Support a Cost-Effective, Non-Destructive Evaluation Approach for Predicting Bolt Failure in Highway Bridges

A. Elyea, B. Doubek, G. Hubbard, and D. Ozevin
Department of Civil Engineering
University of Illinois at Chicago
Chicago, IL

The development of a quantitative nondestructive evaluation method, as an alternative to visual inspection, for inspecting pre-tensioned bolts in fracture critical bridges is presented. In order to understand the ultrasonic behavior of a wide variety of bolt geometries used in bridges, numerical models of nine different bolt geometries were developed. The numerical models included the ...

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