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dc.contributor.advisorNeal, Steven P.en_US
dc.contributor.authorWagner, John William
dc.date.issued2011
dc.date.submitted2011 Fallen_US
dc.descriptionTitle from PDF of title page (University of Missouri--Columbia, viewed on June 8, 2012).en_US
dc.descriptionThe entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.en_US
dc.descriptionThesis advisor: Dr. Steven P. Nealen_US
dc.descriptionIncludes bibliographical references.en_US
dc.descriptionM. S. University of Missouri--Columbia 2011.en_US
dc.descriptionDissertations, Academic -- University of Missouri--Columbia -- Mechanical and aerospace engineering.en_US
dc.description"December 2011"en_US
dc.description.abstractA polycrystalline metal's grain size affects its mechanical properties; therefore, the ability to effectively and easily monitor grain size during a manufacturing process is critical. Conventional destructive tests utilized for estimating grain size or mechanical properties are expensive and time consuming. Past research has shown some success in nondestructively estimating a metal's mean grain size using attenuation coefficient measurements acquired from ultrasound. Within this research, a water immersion, pulse-echo mode of ultrasonic testing is employed to estimate the mean grain diameter of 5 thin copper-alloy samples using attenuation coefficient measurements. The attenuation coefficients were estimated via spectral analysis of interface reflections. The interface reflections were corrected for reflection and transmission effects, beam field diffraction, and water attenuation effects. An experimental diffraction correction approach and an inverse water attenuation filter accounted for diffraction and water attenuation, respectively. A Leave-One-Out (LOO) cross-validation algorithm was implemented to generate correlation models needed for grain diameter estimation. Models were developed as a function of ultrasonic wavelength and yielded grain diameter estimates for each sample. Estimates were seen to compare favorably with the stated grain diameters of the copper-alloy samples.en_US
dc.format.extentvii, 73 pagesen_US
dc.identifier.otherWagnerJ-120811-T445
dc.identifier.urihttp://hdl.handle.net/10355/14579
dc.publisherUniversity of Missouri--Columbiaen_US
dc.relation.ispartof2011 Freely available theses (MU)en_US
dc.relation.ispartofcommunityUniversity of Missouri-Columbia. Graduate School. Theses and Dissertations. Theses. 2011 Theses
dc.subjectattenuation coefficienten_US
dc.subjectnon-destructive evaluationen_US
dc.subjectsignal processingen_US
dc.subjectpolycrystalline metalen_US
dc.titleMean grain size estimation for copper-alloy samples based on attenuation coefficient estimatesen_US
dc.typeThesisen_US
thesis.degree.disciplineMechanical and aerospace engineeringen_US
thesis.degree.disciplineMechanical and aerospace engineeringeng
thesis.degree.grantorUniversity of Missouri--Columbiaen_US
thesis.degree.levelMastersen_US
thesis.degree.nameM.S.en_US


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