Symbolic and Numeric Solutions of Modified Bang-Bang Control Strategies for Performance-Based Assessment of Base-Isolated Structures

Simple item page
dc.contributor.advisorAustin, Mark Aen_US
dc.contributor.authorSebastianelli, Jr., Robert Richarden_US
dc.contributor.departmentCivil Engineeringen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.date.accessioned2005-08-03T13:49:26Z
dc.date.available2005-08-03T13:49:26Z
dc.date.issued2005-04-14en_US
dc.description.abstractThis work explores symbolic and numeric solutions to the Lyapunov matrix equation as it applies to performance-based assessment of base-isolated structures supplemented by modified bang-bang control. Traditional studies of this type rely on numeric simulations alone. This study is the first to use symbolic analysis as a means of identifying key "cause and effect" relationships existing between parameters of the active control problem and the underlying differential equations of motion. We show that symbolic representations are very lengthy, even for structures having a small number of degrees of freedom. However, under certain simplifying assumptions, symbolic solutions to the Lyapunov matrix equation assume a greatly simplified form (thereby avoiding the need for computational solutions). Regarding the behavior of the bang-bang control strategy, further analysis shows: (1) for a 1-DOF system, the actuator force acts very nearly in phase, but in opposite direction to the velocity (90 degrees out of phase and in opposite direction to the displacement), and (2) for a wide range of 2-DOF nonlinear base-isolated models, bang-bang control is insensitive to nonlinear deformations in the isolator devices. Through nonlinear time-history analysis, we see that one- and two-DOF models are good indicators of behavior in higher DOF models. An analytical framework for system assessment through energy- and power-balance analysis is formulated. Computational experiments on base-isolated systems are conducted to identify and quantitatively evaluate situations when constant stiffness bang-bang control can significantly enhance overall performance, compared to base isolation alone, and assess the ability of present-day actuator technologies to deliver actuator power requirements estimated through simulation.en_US
dc.format.extent1809272 bytes
dc.format.mimetypeapplication/pdf
dc.identifier.urihttp://hdl.handle.net/1903/2390
dc.language.isoen_US
dc.subject.pqcontrolledEngineering, Civilen_US
dc.subject.pquncontrolledstructural controlen_US
dc.subject.pquncontrolledbase-isolated structuresen_US
dc.subject.pquncontrolledlyapunov equationen_US
dc.subject.pquncontrolledbang-bang controlen_US
dc.subject.pquncontrolledsymbolic analysisen_US
dc.subject.pquncontrolledenergy-balance analysisen_US
dc.titleSymbolic and Numeric Solutions of Modified Bang-Bang Control Strategies for Performance-Based Assessment of Base-Isolated Structuresen_US
dc.typeDissertationen_US

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
umi-umd-2251.pdf
Size:
1.73 MB
Format:
Adobe Portable Document Format
Download

Collections

UMD Theses and Dissertations
Civil & Environmental Engineering Theses and Dissertations