Simultaneous active passive/control of extensional and flexural power flows in infinite thin beams

Simple item page
dc.contributor.authorDeneufve, Florence L.en
dc.contributor.committeechairFuller, Christopher R.en
dc.contributor.committeememberBurdisso, Ricardo A.en
dc.contributor.committeememberGuigou, Catherine R. J.en
dc.contributor.departmentMechanical Engineeringen
dc.date.accessioned2014-03-14T21:29:15Zen
dc.date.adate2009-02-13en
dc.date.available2014-03-14T21:29:15Zen
dc.date.issued1996-07-15en
dc.date.rdate2009-02-13en
dc.date.sdate2009-02-13en
dc.description.abstractPassive control techniques to minimize structural vibrations are limited with respect to the amount of attenuation obtained especially in the low-frequency region but do not require adding any power. Active control methods are effective for reducing structural vibrations, especially at low frequencies, but may require significant control effort. Thus, passive and active control methods have complementary frequency ranges of application. This research consists of combining active and passive control techniques to simultaneously attenuate extensional and flexural power flows in infinite thin beams and determine the advantages and disadvantages of such a combination. An analytical model is developed for an infinite beam with a passive insert of high damping placed at some distance from a point force excitation (passive approach). The passive control of vibrations results in a reduction of both extensional and flexural power flows downstream of the passive material discontinuity. The simultaneous active control of extensional and flexural waves, using two co-located independent piezoceramic actuators bonded to the surface of the beam, is theoretically studied. The active control model shows that the use of two independent piezoceramic actuators allows complete cancellation of the total power flow (sum of the extensional and flexural power flows) downstream of the actuators. The combination of passive and active control methods for three different configurations (actuators located upstream of, downstream of, and on the passive insert) is investigated and complete control of the total power flow is again achieved. The results demonstrate that in the case of the actuators bonded to the passive material discontinuity, the active/passive combination has great potential for reducing the control effort required for the active controller. Finally, an approximation of the influence of heavy fluid flanking paths on the optimal active/passive system is developed by simulation of these flanking paths using axial and torsional springs. This last study shows that both axial and torsional springs will result in modification of the control effort required by the actuators if their respective stiffness is greater than the equivalent stiffness of the section in parallel with the springs.en
dc.description.degreeMaster of Scienceen
dc.format.extentxii, 151 leavesen
dc.format.mediumBTDen
dc.format.mimetypeapplication/pdfen
dc.identifier.otheretd-02132009-172054en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-02132009-172054/en
dc.identifier.urihttp://hdl.handle.net/10919/41072en
dc.language.isoenen
dc.publisherVirginia Techen
dc.relation.haspartLD5655.V855_1996.D464.pdfen
dc.relation.isformatofOCLC# 35950193en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectvibration controlen
dc.subjectactive/passive controlen
dc.subjectsmart structuresen
dc.subject.lccLD5655.V855 1996.D464en
dc.titleSimultaneous active passive/control of extensional and flexural power flows in infinite thin beamsen
dc.typeThesisen
dc.type.dcmitypeTexten
thesis.degree.disciplineMechanical Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
LD5655.V855_1996.D464.pdf
Size:
18.04 MB
Format:
Adobe Portable Document Format
Description:
Download

Collections

Masters Theses