@phdthesis{Habtemariam,
  author    = {Habtemariam, Abinet Kifle},
  title     = {Generalized Beam Theory for the analysis of thin-walled circular pipe members},
  doi       = {10.25643/bauhaus-universitaet.4572},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220127-45723},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  pages     = {188},
  abstract  = {The detailed structural analysis of thin-walled circular pipe members often requires the use of a shell or solid-based finite element method. Although these methods provide a very good approximation of the deformations, they require a higher degree of discretization which causes high computational costs. On the other hand, the analysis of thin-walled circular pipe members based on classical beam theories is easy to implement and needs much less computation time, however, they are limited in their ability to approximate the deformations as they cannot consider the deformation of the cross-section. This dissertation focuses on the study of the Generalized Beam Theory (GBT) which is both accurate and efficient in analyzing thin-walled members. This theory is based on the separation of variables in which the displacement field is expressed as a combination of predetermined deformation modes related to the cross-section, and unknown amplitude functions defined on the beam's longitudinal axis. Although the GBT was initially developed for long straight members, through the consideration of complementary deformation modes, which amend the null transverse and shear membrane strain assumptions of the classical GBT, problems involving short members, pipe bends, and geometrical nonlinearity can also be analyzed using GBT. In this dissertation, the GBT formulation for the analysis of these problems is developed and the application and capabilities of the method are illustrated using several numerical examples. Furthermore, the displacement and stress field results of these examples are verified using an equivalent refined shell-based finite element model. The developed static and dynamic GBT formulations for curved thin-walled circular pipes are based on the linear kinematic description of the curved shell theory. In these formulations, the complex problem in pipe bends due to the strong coupling effect of the longitudinal bending, warping and the cross-sectional ovalization is handled precisely through the derivation of the coupling tensors between the considered GBT deformation modes. Similarly, the geometrically nonlinear GBT analysis is formulated for thin-walled circular pipes based on the nonlinear membrane kinematic equations. Here, the initial linear and quadratic stress and displacement tangent stiffness matrices are built using the third and fourth-order GBT deformation mode coupling tensors. Longitudinally, the formulation of the coupled GBT element stiffness and mass matrices are presented using a beam-based finite element formulation. Furthermore, the formulated GBT elements are tested for shear and membrane locking problems and the limitations of the formulations regarding the membrane locking problem are discussed.},
  subject      = {Finite-Elemente-Methode},
  language  = {en}
}
@misc{Ullrich2005,
  type      = {Master Thesis},
  author    = {Ullrich, Carmen},
  title     = {Dynamische Analyse der Sprottetalbr{\"u}cke},
  doi       = {10.25643/bauhaus-universitaet.726},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-7268},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  year      = {2005},
  abstract  = {Die vorliegende Arbeit besch{\"a}ftigt sich mit der dynamischen Analyse der Sprottetalbr{\"u}cke infolge aufgetretener Asphaltsch{\"a}den. Sie beinhaltet die Erstellung eines FE-Modells, der Darstellung der theoretischen Grundlagen der Dynamik sowie die Auswertung von berechneten Eigenformen und Asphaltspannungen unter Ber{\"u}cksichtigung der derzeit g{\"u}ltigen Normen.},
  subject      = {Finite-Elemente-Methode},
  language  = {de}
}
@misc{Wehner2006,
  type      = {Master Thesis},
  author    = {Wehner, Diana},
  title     = {Dynamische Analyse der Dreiturmanlage der St. Severikirche in Erfurt},
  doi       = {10.25643/bauhaus-universitaet.741},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-7410},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  year      = {2006},
  abstract  = {Im Zusammenhang mit der gegenw{\"a}rtigen Zustandsbewertung und geplanten Sanierung der Dreiturmanlage der St. Severikirche in Erfurt wird eine dynamische Analyse unter Glockenl{\"a}uten mit Hilfe eines Finite-Elemente-Modells durchgef{\"u}hrt. Mit diesem unter Verwendung des Programms SLang erstellten FE-Modell wird das Schwingungsverhalten der Dreiturmanlage nachgebildet. Dabei dient als Grundlage die zuvor erfolgte Schwingungsmessung. Mit dem angepassten Modell werden schwingungsreduzierende Maßnahmen hinsichtlich ihrer Wirksamkeit untersucht und bewertet. Weiterhin wird an Ersatzsystemen die aktive Schwingungsisolierung mittels Glockenstuhlunterkonstruktion und der Einbau eines passiven Tilgerd{\"a}mpfers betrachtet.},
  subject      = {Dynamische Analyse},
  language  = {de}
}