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dc.contributor.advisorNeal, Steven P.eng
dc.contributor.authorWagner, John Williameng
dc.date.issued2011eng
dc.date.submitted2011 Falleng
dc.descriptionTitle from PDF of title page (University of Missouri--Columbia, viewed on June 8, 2012).eng
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.eng
dc.descriptionThesis advisor: Dr. Steven P. Nealeng
dc.descriptionIncludes bibliographical references.eng
dc.descriptionM. S. University of Missouri--Columbia 2011.eng
dc.descriptionDissertations, Academic -- University of Missouri--Columbia -- Mechanical and aerospace engineering.eng
dc.description"December 2011"eng
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.eng
dc.format.extentvii, 73 pageseng
dc.identifier.otherWagnerJ-120811-T445eng
dc.identifier.urihttp://hdl.handle.net/10355/14579eng
dc.publisherUniversity of Missouri--Columbiaeng
dc.relation.ispartof2011 Freely available theses (MU)eng
dc.relation.ispartofcommunityUniversity of Missouri-Columbia. Graduate School. Theses and Dissertations. Theses. 2011 Theseseng
dc.subjectattenuation coefficienteng
dc.subjectnon-destructive evaluationeng
dc.subjectsignal processingeng
dc.subjectpolycrystalline metaleng
dc.titleMean grain size estimation for copper-alloy samples based on attenuation coefficient estimateseng
dc.typeThesiseng
thesis.degree.disciplineMechanical and aerospace engineering (MU)eng
thesis.degree.grantorUniversity of Missouri--Columbiaeng
thesis.degree.levelMasterseng
thesis.degree.nameM.S.eng


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