eprintid: 67
rev_number: 4
eprint_status: archive
userid: 4
dir: disk0/00/00/00/67
datestamp: 2006-06-19
lastmod: 2015-05-29 19:46:38
status_changed: 2009-04-08 16:53:28
type: report
metadata_visibility: show
item_issues_count: 0
creators_name: Allwright, David
creators_name: Jones, Gareth
creators_name: Parnell, William
creators_id: allwrigh@maths.ox.ac.uk
creators_id: jonesg@maths.ox.ac.uk
creators_id: 
contributors_name: Abrahams, David
contributors_name: Bell, Chris
contributors_name: Bodai, Tamas
contributors_name: Bond, Philip
contributors_name: Hazel, Andrew
contributors_name: Novokshanov, Roman
contributors_name: Parker, David
contributors_name: Perrey-Debain, Emmanuel
contributors_name: Veitch, Ben
contributors_id: 
contributors_id: bellc@maths.ox.ac.uk
contributors_id: 
contributors_id: 
contributors_id: 
contributors_id: 
contributors_id: 
contributors_id: 
contributors_id: 
title: Acoustic scattering from a strained region
ispublished: pub
subjects: materials
subjects: aerodef
studygroups: esgi53
companyname: Thales Underwater Systems
full_text_status: public
abstract: A composite material consists of a rubber filled with gas-filled microspheres. In underwater applications it is compressed hydrostatically by a pressure that may be not insignificant compared with the shear modulus of the rubber, so large strains are produced around each spherical inclusion. When these spherical inclusions scatter an incident acoustic wave, the strained region around an inclusion has had its elastic properties altered by the large static strain. Thales Underwater Systems asked the Study Group to address the question of how this strained region affects the elastic scattering, bearing in mind that the dynamic shear modulus  differs from its static value.
problem_statement: A composite material consists of a rubber filled with gas-filled microspheres. In underwater applications it is compressed hydrostatically by a pressure that may be not insignificant compared with the shear modulus of the rubber, so large strains are produced around each spherical inclusion. When these spherical inclusions scatter an incident acoustic wave, the strained region around an inclusion has had its elastic properties altered by the large static strain, and the Study Group was asked to address the question of how this strained region affects the elastic scattering, bearing in mind that the dynamic shear modulus differs from its static value. The acoustic wavelength is large compared with the diameter of the spherical inclusions and, for the purposes of the Study Group, scattering by just a single microsphere was considered. The Study Group showed that for the monopole scattering strength it was enough to use the dynamic shear modulus in place of the static value in the  existing approach, and also obtained the equations that would have to be tackled for finding the dipole and other scattering strengths.
date: 2006
date_type: published
pages: 14
citation:   Allwright, David and Jones, Gareth and Parnell, William  (2006) Acoustic scattering from a strained region.  [Study Group Report]     
document_url: http://miis.maths.ox.ac.uk/miis/67/1/Thales-report.pdf