Evaluating the bonding condition of NASA spray on foam insulation using audio frequency sound absorption measurements

dc.contributor.author Thompson, Todd
dc.contributor.department Mechanical Engineering
dc.date 2020-11-09T01:32:57.000
dc.date.accessioned 2021-02-26T09:01:08Z
dc.date.available 2021-02-26T09:01:08Z
dc.date.copyright Sat Jan 01 00:00:00 UTC 2005
dc.date.issued 2005-01-01
dc.description.abstract <p>The bonding condition of the spray on foam insulation (SOFI) used to insulate the external tank of the NASA space shuttle can be found by using the audio frequency sound absorption coefficient. The ASTM El050 standard method for sound absorption measurements was used with an open ended one inch diameter cast acrylic impedance tube sealed to the SOFI with closed cell PVC foam. Two artificially disbonded locations, measuring 1.0 inch by 5.5 inches by 0.0625 inches and 2.0 inches by 8.0 inches by 0.0625 inches, were detected by peaks in the sound absorption coefficient spectrum. The peaks in the sound absorption spectrum between 1000 Hz and 4000 Hz were 25% to 50% higher over disbonded areas when compared to bonded locations. The maximum and minimum sound absorption levels for the foam ranged between approximately 0.1 and 0.3. The entire sample was scanned using the sound absorption peaks as indicators. Samples of 2 inch thick polystyrene foam were used with different sized defects at different locations in the foam to relate defect size and location to peaks in absorption coefficient spectrum.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/rtd/20956/
dc.identifier.articleid 21955
dc.identifier.contextkey 20115428
dc.identifier.doi https://doi.org/10.31274/rtd-20201107-513
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath rtd/20956
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/98323
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/rtd/20956/Thompson_ISU_2005_T565.pdf|||Fri Jan 14 22:30:43 UTC 2022
dc.subject.keywords Mechanical engineering
dc.title Evaluating the bonding condition of NASA spray on foam insulation using audio frequency sound absorption measurements
dc.type article
dc.type.genre thesis
dspace.entity.type Publication
relation.isOrgUnitOfPublication 6d38ab0f-8cc2-4ad3-90b1-67a60c5a6f59
thesis.degree.discipline Mechanical Engineering
thesis.degree.level thesis
thesis.degree.name Master of Science
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