Show simple item record

dc.contributor.authorLomenzo, Richard A. Jr.en_US
dc.date.accessioned2014-03-14T21:37:24Z
dc.date.available2014-03-14T21:37:24Z
dc.date.issued1994-04-05en_US
dc.identifier.otheretd-06102009-063143en_US
dc.identifier.urihttp://hdl.handle.net/10919/42988
dc.description.abstract

Poisson's ratio for aluminum is estimated from velocity proflle measurements of a free-free beam under dynamic loading conditions A weighted least-squares method is used to select a beam model which is subsequently used to determine the transverse and anticlastic radii of curvature. The model of the beam velocity profile is selected using forward regression with the possible regressor set formed by products of Legendre polynomials in x and y, the two-dimensional coordinates of the beam. The resulting model is manipulated to extract the transverse and anticlastic radii of curvature of the beam which are then used to find local and global estimates of Poisson's ratio. Estimates for Poisson's ratio are found for three different forcing frequencies and three force amplitudes at each frequency. The frequencies selected correspond to the frequencies of the operating shapes dominated by the flrst, second, and third bending modes. A statistical analysis is performed to assess the quality of the estimates of Poisson's ratio.

Results show that the estimates of Poissonfs ratio are dependent on the forcing frequency and forcing amplitude. All estimates are below the accepted value of .33 for aluminum. Contributions of plate modes adversely affect the estimates. Estimates based on the first and third operating shapes exhibit a lower variance than the estimate based on the second operating shapes.

en_US
dc.format.mediumBTDen_US
dc.publisherVirginia Techen_US
dc.relation.haspartLD5655.V855_1994.L664.pdfen_US
dc.subjectPoisson processesen_US
dc.subject.lccLD5655.V855 1994.L664en_US
dc.titleDynamic measurement and characterization of Poisson's ratioen_US
dc.typeThesisen_US
dc.contributor.departmentMechanical Engineeringen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineMechanical Engineeringen_US
dc.contributor.committeechairCudney, Harley H.en_US
dc.contributor.committeememberWicks, Alfred L.en_US
dc.contributor.committeememberRobertshaw, Harry H.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-06102009-063143/en_US
dc.date.sdate2009-06-10en_US
dc.date.rdate2009-06-10
dc.date.adate2009-06-10en_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record