Browsing NTNU Open by Author "Berstad, Torodd"

Now showing items 1-20 of 20

    • CO2 pipeline integrity: A coupled fluid-structure model using a reference equation of state for CO2 

      Aursand, Eskil; Aursand, Peder; Berstad, Torodd; Dørum, Cato; Hammer, Morten; Munkejord, Svend Tollak; Nordhagen, Håkon Ottar (Journal article; Peer reviewed, 2013)
      We present a coupled fluid-structure model to study crack propagation and crack arrest in pipelines. Numerical calculations of crack arrest, crack velocity and pressure profiles have been performed for steel pipes with an ...

    • CO2 pipeline integrity: A new evaluation methodology 

      Berstad, Torodd; Dørum, Cato; Jakobsen, Jana Poplsteinova; Kragset, Steinar; Li, Hailong; Lund, Halvor; Morin, Alexandre; Munkejord, Svend Tollak; Mølnvik, Mona Jacobsen; Nordhagen, Håkon Ottar; Østby, Erling (Journal article; Peer reviewed, 2011)
      A coupled fluid-structure model for pipeline integrity simulations has been developed. The pipe material and fracture propagation have been modelled using the finite-element method with a local fracture criterion. The ...

    • Constitutive modeling of aluminum foam including fracture and statistical variation of density 

      Reyes, Aase Gavina Roberg; Hopperstad, Odd Sture; Berstad, Torodd; Hanssen, Arve Grønsund; Langseth, Magnus (Journal article; Peer reviewed, 2003)
      An existing constitutive model applicable for aluminum foam was evaluated. The model was implemented in LS-DYNA, and several test cases were analyzed and compared to experimental data. The numerical analyses consisted of ...

    • Coupled finite element-discrete element method (FEM/DEM) for modelling hypervelocity impacts 

      Færgestad, Rannveig Marie; Holmen, Jens Kristian; Berstad, Torodd; Cardone, Tiziana; Ford, Kevin Anthony; Børvik, Tore (Peer reviewed; Journal article, 2022)
      Hypervelocity impacts (HVIs) from orbital debris are an increasing threat to current and future missions in low Earth orbit, making spacecraft shielding vital for future space exploration efforts. A debris shield is a ...

    • Coupled fluid-solid modelling of the valve dynamics in reciprocating compressors 

      Ervik, Åsmund; Saai, Afaf; Berstad, Torodd; Meyer, Ole; Tsuji, Takuma; Oku, Tatsuya; Hattori, Kazuhiro; Yamada, Kazuya; Delhaye, Virgile Roger; Nekså, Petter (Chapter, 2022)
      A novel method coupling computational fluid dynamics (CFD) and finite element method (FEM) was developed to account for the complex physics of the reciprocating compressor. The developed method is based on data exchange ...

    • Finite element modelling of steel bridge structures exposed to ship collisions 

      Ofstad, Kevin Mandt (Master thesis, 2018)
      The behavior of the Bressan-Williams-Hill fracture criterion (BWH), which is often used in simulating ship collisions, was studied by modeling and studying existing experiments done on the subject. Three experiments are ...

    • Forming limit diagrams with an FE-based approach for sheets under non-proportional loading 

      Reyes, Aase Gavina Roberg; Hopperstad, Odd Sture; Berstad, Torodd; Lademo, Odd-Geir (Chapter, 2009)
      In this study, LS-DYNA was used to predict the experimental forming limit diagrams (FLDs) for prestrained sheets in aluminum alloy Al2008-T4 found by Graf and Hosford [1]. The original data of Graf and Hosford [1] includes ...

    • Impact behaviour of foam-based protective structures 

      Berdal, Sindre; Bjørgo, Lars Einar Uhlen (Master thesis, 2017)
      Foams are three dimensional cellular materials, with cell walls made up of a solid or liquid material and cells containing a gas or liquid. The solid material can be anything from a metal to a ceramic. Metallic and polymeric ...

    • Low-velocity impact behaviour and failure of stiffened steel plates 

      Gruben, Gaute; Sølvernes, S; Berstad, Torodd; Morin, David; Hopperstad, Odd Sture; Langseth, Magnus (Journal article; Peer reviewed, 2017)
      The behaviour and failure of stiffened steel plates subjected to transverse loading by an indenter is studied in this paper. Low-velocity dynamic and quasi-static tests of stiffened plates with geometry adopted from a ...

    • On the ballistic perforation resistance of a sandwich structure with aluminium skins and aluminium foam core 

      Brekken, Kristoffer Aune; Bakk, Maria S.; Dey, Sumita; Berstad, Torodd; Reyes, Aase; Børvik, Tore (Peer reviewed; Journal article, 2023)
      Sandwich structures have proven to be excellent energy absorbents and are found in various protective solutions. In this study, an inhomogeneous aluminium foam was used as core material in a sandwich panel with skins of ...

    • On the spatio-temporal characteristics of the Portevin-Le Chatelier effect in aluminium alloy AA5182: An experimental and numerical study 

      Xu, Jianbin; Hopperstad, Odd Sture; Holmedal, Bjørn; Berstad, Torodd; Manik, Tomas; Marthinsen, Knut (Peer reviewed; Journal article, 2023)
      The Portevin–Le Chatelier (PLC) effect and its spatio-temporal characteristics in the aluminium alloy AA5182 are studied experimentally and numerically in the current work. An extremely high-frequency camera (up to 1000 ...

    • Performance of thin blast-loaded steel plates after ballistic impact from small-arms projectiles 

      Elveli, Benjamin Stavnar; Berstad, Torodd; Børvik, Tore; Aune, Vegard (Peer reviewed; Journal article, 2023)
      It is known from real blast-load events that the combined effect of fragment impact and blast loading is more severe than the effect of the blast loading alone. The present study investigates this effect by comparing the ...

    • A pragmatic orthotropic elasticity-based damage model with spatially distributed properties applied to short glass-fibre reinforced polymers 

      Holmström, Petter Henrik; Clausen, Arild Holm; Berstad, Torodd; Morin, David; Hopperstad, Odd Sture (Peer reviewed; Journal article, 2021)
      This article presents a simple progressive damage model for quasi-brittle materials, combining orthotropic elasticity with a scalar damage model including spatial variation of the damage initiation strain and the crack ...

    • Prediction of necking for two aluminum alloys under non-proportional loading by using an FE-based approach 

      Reyes, Aase Gavina Roberg; Hopperstad, Odd Sture; Berstad, Torodd; Lademo, Odd-Geir (Journal article; Peer reviewed, 2008)
      Forming Limit Diagrams (FLDs) were found numerically for sheets under non-proportional loading by means of an FE-based Marciniak–Kuczynski (M-K) analysis. The material model used in the analysis includes two instability ...

    • Sandwich panels with polymeric foam cores exposed to blast loading: An experimental and numerical investigation 

      Brekken, Kristoffer Aune; Reyes, Aase Gavina Roberg; Berstad, Torodd; Langseth, Magnus; Børvik, Tore (Peer reviewed; Journal article, 2020)
      Sandwich panels have proven to be excellent energy absorbents. Such panels may be used as a protective structure in, for example, façades subjected to explosions. In this study, the dynamic response of sandwich structures ...

    • Simulering av brudd og sprekkvekst med X-FEM 

      Gjernes, Jo Øivind; Klokk, Erik Remø (Master thesis, 2012)
      X-FEM, den utvidede elementmetoden, er en relativt ny metode for simulering av sprekkvekst. X-FEM bygger på rammeverket til vanlig elementmetode, FEM. I X-FEM berikes nodene i et element for å inkludere diskontinuiteter ...

    • Testing and Modelling of Thick Aluminium Castings Under Impact Loadings 

      Gjertsen, Bjørn; Tjessem, Sondre (Master thesis, 2020)
      Denne masteroppgaven har som mål å etablere og forbedre en elementmetode (FE) modell som fanger opp oppførselen til en bilfelg utsatt for støtlast, ved bruk av “state-of-the-art” modelleringsteknikker. Utvikling er en del ...

    • Testing and Modelling of Thick Aluminium Castings Under Impact Loadings 

      Gjertsen, Bjørn; Tjessem, Sondre (Master thesis, 2020)
      Denne masteroppgaven har som mål å etablere og forbedre en elementmetode (FE) modell som fanger opp oppførselen til en bilfelg utsatt for støtlast, ved bruk av “state-of-the-art” modelleringsteknikker. Utvikling er en del ...

    • Thin steel plates exposed to combined ballistic impact and partially confined airblast loading 

      Elveli, Benjamin Stavnar; Vestrum, Ole; Hauge, Knut Ove; Berstad, Torodd; Børvik, Tore; Aune, Vegard (Peer reviewed; Journal article, 2023)
      Pre-formed defects created by high-velocity impact have the potential to reduce the structural integrity of lightweight, flexible structures. This study evaluates the effect of complex, partially confined detonations on ...

    • Void nucleation and growth in mineral-filled PVC - An experimental and numerical study 

      Ognedal, Anne Serine; Clausen, Arild Holm; Berstad, Torodd; Seelig, Thomas; Hopperstad, Odd Sture (Journal article; Peer reviewed, 2014)
      The nucleation and growth of voids in mineral-filled PVC have been investigated through experimental and numerical studies. Uniaxial tensile specimens were deformed in tension to different elongation levels and then unloaded. ...