Title:
Methods for increased computational efficiency of multibody simulations

dc.contributor.advisor Bauchau, Olivier A.
dc.contributor.author Epple, Alexander en_US
dc.contributor.committeeMember Makeev, Andrew
dc.contributor.committeeMember Bottasso, Carlo L.
dc.contributor.committeeMember Hodges, Dewey H.
dc.contributor.committeeMember Ruzzene, Massimo
dc.contributor.department Aerospace Engineering en_US
dc.date.accessioned 2009-01-22T15:43:35Z
dc.date.available 2009-01-22T15:43:35Z
dc.date.issued 2008-08-08 en_US
dc.description.abstract This thesis is concerned with the efficient numerical simulation of finite element based flexible multibody systems. Scaling operations are systematically applied to the governing index-3 differential algebraic equations in order to solve the problem of ill conditioning for small time step sizes. The importance of augmented Lagrangian terms is demonstrated. The use of fast sparse solvers is justified for the solution of the linearized equations of motion resulting in significant savings of computational costs. Three time stepping schemes for the integration of the governing equations of flexible multibody systems are discussed in detail. These schemes are the two-stage Radau IIA scheme, the energy decaying scheme, and the generalized-α method. Their formulations are adapted to the specific structure of the governing equations of flexible multibody systems. The efficiency of the time integration schemes is comprehensively evaluated on a series of test problems. Formulations for structural and constraint elements are reviewed and the problem of interpolation of finite rotations in geometrically exact structural elements is revisited. This results in the development of a new improved interpolation algorithm, which preserves the objectivity of the strain field and guarantees stable simulations in the presence of arbitrarily large rotations. Finally, strategies for the spatial discretization of beams in the presence of steep variations in cross-sectional properties are developed. These strategies reduce the number of degrees of freedom needed to accurately analyze beams with discontinuous properties, resulting in improved computational efficiency. en_US
dc.description.degree Ph.D. en_US
dc.identifier.uri http://hdl.handle.net/1853/26532
dc.publisher Georgia Institute of Technology en_US
dc.subject Property smoothing en_US
dc.subject Mesh optimization en_US
dc.subject Beams en_US
dc.subject Flexible multibody dynamics en_US
dc.subject Finite element method en_US
dc.subject Scaling en_US
dc.subject Augmented Lagrangian en_US
dc.subject Constraints en_US
dc.subject Differential algebraic equations en_US
dc.subject DAE en_US
dc.subject Time stepping schemes en_US
dc.subject Finite rotations en_US
dc.subject Interpolation en_US
dc.subject.lcsh Interpolation
dc.subject.lcsh Approximation theory
dc.subject.lcsh Differential Algebraic equations
dc.subject.lcsh Algorithms
dc.subject.lcsh Iterative methods (Mathematics)
dc.subject.lcsh Mathematical optimization
dc.title Methods for increased computational efficiency of multibody simulations en_US
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.corporatename College of Engineering
local.contributor.corporatename Daniel Guggenheim School of Aerospace Engineering
local.relation.ispartofseries Doctor of Philosophy with a Major in Aerospace Engineering
relation.isOrgUnitOfPublication 7c022d60-21d5-497c-b552-95e489a06569
relation.isOrgUnitOfPublication a348b767-ea7e-4789-af1f-1f1d5925fb65
relation.isSeriesOfPublication f6a932db-1cde-43b5-bcab-bf573da55ed6
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