Gelat, P, Saffari, N, Hutchins, DA et al. (6 more authors) (2015) The Dynamic Excitation of a Chain of Pre-Stressed Spheres for Biomedical Ultrasound Applications: Contact Mechanics Finite Element Analysis and Validation. In: 2015 IEEE International Ultrasonics Symposium (IUS). , 21-24 Oct 2015, Taipei, Taiwan. IEEE ISBN 978-1-4799-8182-3
Abstract
There has been recent interest in the transmission of acoustic signals along a chain of spheres to produce waveforms of relevance to biomedical ultrasound applications. Effects which arise as a result of Hertzian contact between adjacent spheres can potentially change the nature of the signal as it propagates down the chain. The possibility thus exists of generating signals with a different harmonic content to the signal input into one end of the chain. This transduction mechanism has the potential to be of use in both diagnostic and therapeutic ultrasound applications, and is the object of the study presented here. The nonlinear dynamics of granular chains can be treated using discrete mechanics models. However, in cases where the underlying assumptions of these models no longer hold, and where geometries are more complex, a more comprehensive numerical solution must be sought. Contact mechanics problems can efficiently be treated using the finite element method. The latter was used to investigate the dynamics of a pre-stressed chain of six, 1 mm diameter stainless steel spheres excited at one end using a tone burst displacement signal with a fundamental frequency of 73 kHz. The final sphere of the chain was assumed to be in contact with a cylindrical matching layer radiating into a half-space of fluid with the properties of water. After addition of the fluid loading, radiated acoustic pressures in the medium were predicted. Comparison with experimental results suggests that finite element analysis is a suitable tool for investigating the design and performance of contact mechanics based transducers. Nevertheless, a better handle on the model input parameters as well as an improved experimental protocol are required to fully validate the model.
Metadata
Item Type: | Proceedings Paper |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2015, IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. |
Keywords: | Finite element analysis; Granular chain; Nonlinear systems; Ultrasonic transducers |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Electronic & Electrical Engineering (Leeds) > Institute of Communication & Power Networks (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 20 Jul 2016 14:02 |
Last Modified: | 16 Jan 2018 16:26 |
Published Version: | http://doi.org/10.1109/ULTSYM.2015.0319 |
Status: | Published |
Publisher: | IEEE |
Identification Number: | 10.1109/ULTSYM.2015.0319 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:101048 |