Imperial College London
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ProfessorMichaelLowe

Faculty of Engineering, Department of Mechanical Engineering

Head of Department of Mechanical Engineering
 
 
 
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Contact

 

+44 (0)20 7594 7000m.lowe Website

 
 
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Assistant

 

Ms Nina Hancock +44 (0)20 7594 7068

 
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Location

 

577DCity and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Huang:2020:10.1121/10.0002916,
author = {Huang, M and Sha, G and Huthwaite, P and Rokhlin, S and Lowe, MJS},
doi = {10.1121/10.0002916},
journal = {Journal of the Acoustical Society of America},
pages = {3645--3662},
title = {Elastic wave velocity dispersion in polycrystals with elongated grains: Theoretical and numerical analysis},
url = {http://dx.doi.org/10.1121/10.0002916},
volume = {148},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The phase velocity dispersion of longitudinal waves in polycrystals with elongated grains of arbitrary crystallographic symmetry is studied in all frequency ranges by the theoretical second-order approximation (SOA) and numerical three-dimensional finite element (FE) models. The SOA and FE models are found to be in excellent agreement for three studied polycrystals: cubic Al, Inconel, and a triclinic material system. A simple Born approximation for the velocity, not containing the Cauchy integrals, and the explicit analytical quasi-static velocity limit (Rayleigh asymptote) are derived. As confirmed by the FE simulations, the velocity limit provides an accurate velocity estimate in the low-frequency regime where the phase velocity is nearly constant on frequency; however, it exhibits dependence on the propagation angle. As frequency increases, the phase velocity increases towards the stochastic regime and then, with further frequency increase, behaves differently depending on the propagation direction. It remains nearly constant for the wave propagation in the direction of the smaller ellipsoidal grain radius and decreases in the grain elongation direction. In the Rayleigh and stochastic frequency regimes, the directional velocity change shows proportionalities to the two elastic scattering factors even for the polycrystal with the triclinic grain symmetry.
AU  - Huang,M
AU  - Sha,G
AU  - Huthwaite,P
AU  - Rokhlin,S
AU  - Lowe,MJS
DO  - 10.1121/10.0002916
EP  - 3662
PY  - 2020///
SN  - 0001-4966
SP  - 3645
TI  - Elastic wave velocity dispersion in polycrystals with elongated grains: Theoretical and numerical analysis
T2  - Journal of the Acoustical Society of America
UR  - http://dx.doi.org/10.1121/10.0002916
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000600138400005&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - http://hdl.handle.net/10044/1/85906
VL  - 148
ER  -
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