• A comparative study of beam element formulations for nonlinear analysis: corotatinal vs. geometrically exact formulations 

      Mathisen, Kjell Magne; Bazilevs, Yuri; Haugen, Bjørn; Helgedagsrud, Tore Andreas; Kvamsdal, Trond; Okstad, Knut Morten; Raknes, Siv Bente (Chapter, 2017)
      In this work the geometrically exact three-dimensional beam theory has been used as basis for development of a family of isoparametric higher order large deformation curved beam elements. Geometrically exact three-dimensional ...
    • ALE-VMS methods for wind-resistant design of long-span bridges 

      Helgedagsrud, Tore Andreas; Bazilevs, Yuri; Mathisen, Kjell Magne; Øiseth, Ole (Peer reviewed; Journal article, 2019)
      For unsteady aerodynamics, the Arbitrary Lagrangian-Eulerian Variational Multi-Scale (ALE-VMS) formulation for incompressible flows has proven an accurate and powerful method. In this paper we present an overview of some ...
    • Computational and experimental investigation of free vibration and flutter of bridge decks 

      Helgedagsrud, Tore Andreas; Bazilevs, Yuri; Mathisen, Kjell Magne; Øiseth, Ole (Journal article; Peer reviewed, 2018)
      A modified rigid-object formulation is developed, and employed as part of the fluid–object interaction modeling framework from Akkerman et al. (J Appl Mech 79(1):010905, 2012. https://doi.org/10.1115/1.4005072) to simulate ...
    • Evaluering av utmattingsberegninger for sveiser basert på DnV RP-C203 

      Lanza, Remi Krister Sylvain (Master thesis, 2015)
      I strukturnanalyser er det alltid flere metoder for å estimere strukturens indre spenninger. Noen er mindre nøyaktige, men og mindre komplekse, andre er mer presise men også mer tidskrevende. I denne oppgave skal vi ...
    • Forbedring og kvalitetssikring av programmet fap2D 

      Pedersen, Kristian (Master thesis, 2013)
      Denne rapporten presenterer arbeidet lagt ned i videreutvikling av programmet fap2D, et program for statisk og dynamisk analyse av plane rammekonstruksjoner.Denne rapporten er skrevet for å gi dokumentasjon over ny og ...
    • Implementation of isogeometric thin shell analysis within an object oriented computing environment 

      Haave, Simen Skogholt; Rakvåg, Marit (Master thesis, 2018)
      The drawback in today's computational analysis in structural engineering is that design and analysis are not integrated in a unified platform. A majority of the time spent in structural analysis is used to transform a ...
    • Isogeometric Analysis and Degenerated Mappings 

      Raknes, Siv Bente (Master thesis, 2011)
      In this thesis we have given an introduction to isogeometric finite element analysis on linear elasticity problems in 2D using non uniform rational B-splines (NURBS) as basis functions. We have studied the theory of B-splines ...
    • Isogeometric analysis of finite deformation nearly incompressible solids 

      Mathisen, Kjell Magne; Okstad, Knut Morten; Kvamsdal, Trond; Raknes, Siv Bente (Peer reviewed; Journal article, 2011)
      This paper addresses the use of isogeometric analysis to solve finite deformationsolid mechanics problems, in which volumetric locking may be encountered. The current workis based on the foundation developed in the project ...
    • Isogeometric methods for CFD and FSI-simulation of flow around turbine blades 

      van Opstal, Timo Matteo; Fonn, Eivind; Holdahl, Runar; Kvamsdal, Trond; Kvarving, Arne Morten; Mathisen, Kjell Magne; Nordanger, Knut; Okstad, Knut Morten; Rasheed, Adil; Tabib, Mandar (Journal article; Peer reviewed, 2015)
      Coupled fluid-structure interaction simulations of wind turbines have traditionally been considered computationally too expensive to carry out. However, more powerful computers and better solution techniques based on ...
    • Isogeometric Modeling and Experimental Investigation of Moving-Domain Bridge Aerodynamics 

      Helgedagsrud, Tore Andreas; Akkerman, Ido; Bazilevs, Yuri; Mathisen, Kjell Magne; Øiseth, Ole (Journal article; Peer reviewed, 2019)
      Computational fluid dynamics (CFD) and fluid–structure interaction (FSI) are growing disciplines in the aeroelastic analysis and design of long-span bridges, which, with their bluff body characteristics, offer major ...
    • Modeling and Simulation of Bridge-Section Buffeting Response in Turbulent Flow 

      Helgedagsrud, Tore Andreas; Bazilevs, Yuri; Mathisen, Kjell Magne; Yan, Jinhui; Øiseth, Ole (Peer reviewed; Journal article, 2019)
      Buffeting analysis plays an important role in the wind-resistant design of long-span bridges. While computational methods have been widely used in the study of self-excited forces on bridge sections, there is very little ...
    • Nonlinear Analysis of 3D Beams: A Comparative Study of Geometrically Exact and the Beam Elements in ABAQUS 

      Torp, Anders Pjaaka (Master thesis, 2017)
      For several decades, the finite element method (FEM) has been widely used in nonlinear analysis of three-dimensional (3D) curved beam-like structural systems, subjected to large displacements and strains. Among the numerous ...
    • Nonlinear Isogeometric Analysis vs NFEA of Tubular Joints 

      Ellingsen, Rikke (Master thesis, 2013)
      In 2005, Hughes et al. introduced the isogeometric analysis. One purpose was to eliminate the conversion between geometry model and analysis model in finite element analyses. NURBS (Non-Uniform Rational B-Splines) were ...
    • Nonlinear static and dynamic isogeometric analysis of slender spatial cable and beam type structures 

      Raknes, Siv Bente (Doctoral theses at NTNU;2019:181, Doctoral thesis, 2019)
      In this thesis, a bending-stabilized cable element with three degrees of freedom per control point, and a four degrees of freedom Euler-Bernoulli beam element, has been derived in a dynamic isogeometric setting. The elements ...
    • On Locking-free Methods for Isogeometric Large Deformation Analysis of Geometrically Exact 3D Timoshenko Beams 

      Helgedagsrud, Tore Andreas (Master thesis, 2015)
      In this thesis the geometrically exact 3D shear-flexible beam model is discretized with the Lagrangian and the NURBS basis functions, and has been used as a basis to develop a family of locking-free NURBS-based elements. ...
    • Using ALE-VMS to compute aerodynamic derivatives of bridge sections 

      Helgedagsrud, Tore Andreas; Bazilevs, Yuri; Korobenko, Artem; Mathisen, Kjell Magne; Øiseth, Ole (Journal article; Peer reviewed, 2018)
      Aeroelastic analysis is a major task in the design of long-span bridges, and recent developments in computer power and technology have made Computational Fluid Dynamics (CFD) an important supplement to wind tunnel experiments. ...
    • Using ALE-VMS to compute wind forces on moving bridge decks 

      Helgedagsrud, Tore Andreas; Bazilevs, Yuri; Korobenko, Artem; Mathisen, Kjell Magne; Øiseth, Ole (Chapter, 2017)
      A framework for simulating the forced-vibration wind tunnel experiment using stabilized ALE-VMS techniques has been developed. With a user-defined motion of the bridge deck the problem reduces to a flow computation on a ...
    • Utbedring og uttesting av programmet fap2D 

      Sandviken, Torjus; Skogsrud, Espen Shin (Master thesis, 2014)
      Denne rapporten presenterer arbeidet med å videreutvikle programmet fap2D, et PC-program for statisk og dynamisk analyse av plane rammekonstruksjoner.Arbeidet bygger videre på arbeider utført i tidligere masteroppgaver ...
    • Videreføring av lineær statisk analyse i programmet fap2D 

      Erstad, Frans (Master thesis, 2013)
      Denne rapporten beskriver utviklingen av analysen «sanntids» beregninger i fap2D, et program for statisk og dynamisk analyse av 2D rammekonstruksjoner. I tillegg omhandler den også arbeidet med forbedringer og stabilisering ...
    • Wind forces on bridge decks using state-of-the-art FSI methods 

      Helgedagsrud, Tore Andreas (Doctoral theses at NTNU;2019:180, Doctoral thesis, 2019)
      Several bridges with span widths that challenge present technology are currently under planning in Norway, and wind effects are among the major concerns. Traditionally, wind-structure interactions are studied experimentally ...