Blar i NTNU Open på forfatter "Sævik, Svein"

Viser treff 61-80 av 139

    • Impact analysis of flexible riser 

      Brandt, Ulrikke (Master thesis, 2014)
      Research shows 35% of damage to flexible pipes occurs within the first year. A minimum of these failures are from poor design or manufacturing problems, since factories conduct Factory Acceptance Tests (FAT). Additionally, ...

    • Improved VIV Prediction of Free Spanning Pipelines and Cables 

      Farantos, Christos (Master thesis, 2022)
      Sammendrag Denne oppgaven omhandler validering og kalibrering av en tidsplanmodell for å beregne virvelindusert respons (VIV) av frie spenn i rørledninger utsatt for strømkrefter. Målet med var på den ene siden å presentere ...

    • Improved VIV Response Prediction Using Adaptive Parameters and Data Clustering 

      Wu, Jie; Yin, Decao; Lie, Halvor; Riemer-Sørensen, Signe; Sævik, Svein; Triantafyllou, Michael (Peer reviewed; Journal article, 2020)
      Slender marine structures such as deep-water riser systems are continuously exposed to currents, leading to vortex-induced vibrations (VIV) of the structure. This may result in amplified drag loads and fast accumulation ...

    • Improving Vortex-Induced Vibration Prediction Using Hybrid Analytic 

      Holme, Ole Kristian (Master thesis, 2023)
      Prediksjoner av virvel-induserte vibrasjoner (VIV) er av stor betydning i design- og levetidsberegninger for slanke strukturer i havet. Modellene brukt i dag, har flere forenklinger som gjør at de ikke klarer å beskrive ...

    • In-Line Vibrations of Flexible Pipes 

      Ulveseter, Jan Vidar; Sævik, Svein (Chapter; Peer reviewed, 2017)
      A semi-empirical prediction tool for pure in-line vortex-induced vibrations is under development. The long-term goal is to be able to realistically model the dynamic behavior of free spanning pipelines exposed to arbitrary ...

    • Integrated optimisation design of a dynamic umbilical based on an approximate model 

      Yang, Zhixun; Yan, Jun; Sævik, Svein; Lu, Qingzhen; Ye, Naiquan; Chen, Jinlong; Yue, Qian-Jin (Peer reviewed; Journal article, 2021)
      An optimised design of a dynamic umbilical requires an extreme cross-sectional stress to be maintained within an allowable limit and a fatigue life to be guaranteed to be sufficient. It should be noted that a dynamic ...

    • Investigation on the Performance of the Universal Buoyancy System 

      Staalesen, Odd Eivind Solø (Master thesis, 2014)
      Future increase in the market demand for liquefied natural gas (LNG) will pose new challenges to the existing infrastructure for LNG distribution. The Universal Buoyancy System (UBS) seeks to contribute to the solution of ...

    • Investigations of Shear Interaction and Stress in Flexible Pipes and Umbilicals 

      Dai, Tianjiao (Doctoral theses at NTNU;2018:368, Doctoral thesis, 2018)
      The present thesis deals with numerical modeling and experimental testing related to dynamic stress behavior of flexible pipes and umbilicals, with particular focus on shear interaction and friction effects. For the ...

    • Jordmodeller og utmatning av fritthengende stigerør 

      Grindstad, Anne Cecilie (Master thesis, 2016)
      Denne masteravhandlingen omhandler utvikling og anvendelse av jordmodeller for beskrivelse av jord-stigerør interaksjon. På dypt vann, er jorda bestående av leire noe som introduserer sensitive parameterer. Det gjør ...

    • Mechanical analysis of drilling riser based on pipe-in-pipe model 

      Wang, Huanhuan; Yang, Jin; Sævik, Svein; Leira, Bernt Johan; Zhang, Dongyufu; Hu, Zhiqiang; Xu, Fei; Wang, Wenxing (Journal article, 2021)
      Due to the presence of a drill string inside drilling risers, the mechanical analysis becomes somewhat challenging which has attracted attention from design engineers and drilling operators. The purpose of this study is ...

    • A Methodology for Tuning of Computational Vessel Models Utilizing Wave Measurements From X-Band Marine Radar and Wave Buoy 

      Radhakrishnan, Gowtham; Leira, Bernt Johan; Gao, Zhen; Sævik, Svein; Kaasen, Karl Erik; Christakos, Konstantinos; Dirdal, Johann Alexander (Chapter, 2023)
      Accurate estimation of the wave field and subsequent vessel response prediction are vital for making crucial judgments on the safe and timely execution of marine operations. Decision support systems based on the Response-Based ...

    • motion control during offshore lift operations 

      Andersen, Sten Martin Grønlund (Master thesis, 2017)
      Offshore lifting is present in many offshore operations. Offshore lifting operations is very sensitive to environmental loads which reduces the weather window for the entire operation. The weather criteria for offshore ...

    • Motion Feasibility Framework for Remotely Operated Vehicles Based on Dynamic Positioning Capability 

      Ramírez-Macías, Juan A.; Vásquez, Rafael E.; Sørensen, Asgeir Johan; Sævik, Svein (Peer reviewed; Journal article, 2021)
      Knowing whether a remotely operated vehicle (ROV) is able to operate at certain foreknown environmental conditions is a question relevant to different actors during the vehicle’s life cycle: during design stages, buying ...

    • Motion response prediction of marine vessels based on hydrodynamic models updated through on-site measurements. 

      Radhakrishnan, Gowtham; Leira, Bernt Johan; Gao, Zhen; Sævik, Svein; Gomola, Alojz (Chapter, 2022)
      Decision support systems in offshore vessels utilize wave parameters in combination with physics-based vessel models to predict the vessel behavior prior to the initiation and execution of a marine operation. These predictions ...

    • Non-Linear Clay Soil Model for Lateral Pipe-Soil Interaction 

      Agusta, Arifian; Ji, Guomin; Sævik, Svein (Chapter; Peer reviewed, 2016)
      This paper describes implementation and application of nonlinear lateral soil models for pipeline lateral buckling analysis. Several lateral soil models have been developed in the past and the model developed by Verley is ...

    • NON-LINEAR SOIL MODELS FOR PIPELINE AND RISER ANALYSIS 

      Irman, Arifian Agusta (Master thesis, 2015)
      This thesis describes the development and application of non-linear soil models in pipeline and riser design. A non-linear soil model is typically employed when investigating a complex pipe-soil interaction problem. Two ...

    • Non-linear time domain analysis of cross-flow vortex-induced vibrations 

      Thorsen, Mats Jørgen; Sævik, Svein; Larsen, Carl Martin (Journal article; Peer reviewed, 2017)
      A previously proposed hydrodynamic load model for time domain simulation of cross-flow vortex-induced vibrations (VIV) is modified and combined with Morison's equation. The resulting model includes added mass, drag and a ...

    • Nonlinear bending behavior of a multilayer copper conductor in a dynamic power cable 

      Hu, Haitao; Yan, Jun; Sævik, Svein; Ye, Naiquan; Lu, Qingzhen; Bu, Yufeng (Peer reviewed; Journal article, 2022)
      Reciprocating bending behavior is the main factor leading to the fatigue failure of dynamic power cables. However, in the research on the reciprocating bending behavior of dynamic cables, only the mechanical properties of ...

    • Nonlinear bending behavior of a multilayer copper conductor in a dynamic power cable 

      Hu, Haitao; Yan, Jun; Sævik, Svein; Ye, Naiquan; Lu, Qingzhen; Bu, Yufeng (Journal article; Peer reviewed, 2022)
      Reciprocating bending behavior is the main factor leading to the fatigue failure of dynamic power cables. However, in the research on the reciprocating bending behavior of dynamic cables, only the mechanical properties of ...

    • Numerical analysis of buckling failure in flexible pipe armor wires 

      Yang, Xu; Sævik, Svein; Sun, Liping (Journal article; Peer reviewed, 2015)
      Flexible pipes may be exposed to high axial compression and bending during deep-water installation. As the compression force is mainly sustained by the tensile armor layers, this may result in localized lateral or radial ...