Blar i SINTEF Open på forfatter "Hopperstad, Odd Sture"
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A thermo-elasto-viscoplastic constitutive model for polymers
Johnsen, Joakim; Clausen, Arild Holm; Grytten, Frode; Benallal, Ahmed; Hopperstad, Odd Sture (Journal article; Peer reviewed, 2018) -
Anisotropic tensile failure of metals by the strain localization theory: An application to a high-strength aluminium alloy
Morin, David; Fourmeau, Marion; Børvik, Tore; Benallal, Ahmed; Hopperstad, Odd Sture (Journal article; Peer reviewed, 2018) -
ATLAS of yield surfaces for strongly textured FCC polycrystals
Dumoulin, Stephane; Coudert, Térence; Hopperstad, Odd Sture (Peer reviewed; Journal article, 2019)Discrete yield surfaces for several generic texture components, including randomness, found in aluminium alloys have been generated and used to calibrate the yield function Yld2004-18p. It is generally observed that the ... -
Deformation and strain localization in polycrystals with plastically heterogeneous grains
Khadyko, Mikhail; Marioara, Calin Daniel; Ringdalen, Inga Gudem; Dumoulin, Stephane; Hopperstad, Odd Sture (Peer reviewed; Journal article, 2016)A model of a polycrystalline material is studied, where each grain consists of several zones with different plastic properties. The size and configuration of the zones as well as their properties are mimicking the situation ... -
Detailed investigation of the shearing mechanism of β" precipitates in Al-Mg-Si alloys
Christiansen, Emil; Marioara, Calin Daniel; Ringdalen, Inga Gudem; Bjørge, Ruben; Holmedal, Bjørn; Hopperstad, Odd Sture; Holmestad, Randi (Peer reviewed; Journal article, 2020)The mechanism behind shearing of β'' precipitates in Al-Mg-Si alloys during deformation is investigated by applying advanced transmission electron microscopy (TEM) techniques and frozen phonon multislice TEM image simulations ... -
Ductile Fracture of Steel Sheets under Dynamic Membrane Loading
Gruben, Gaute; Morin, David; Langseth, Magnus; Hopperstad, Odd Sture (Peer reviewed; Journal article, 2017)Failure prediction assessment is conducted based on validated finite element simulations of impact tests performed on 1.8 mm dual-phase and 1.0 mm martensitic steel sheets. The sheets were clamped between two steel rings ... -
Experimental and numerical study on the behaviour of PVC and HDPE in biaxial tension
Ognedal, Anne Serine; Clausen, Arild Holm; Polanco-Loria, Mario A.; Benallal, Ahmed; Raka, Bumedijen; Hopperstad, Odd Sture (Peer reviewed; Journal article, 2012)This paper presents and discusses a set of biaxial tests on two different polymer materials; PVC and HDPE. The biaxial tests are used to evaluate a hyperelastic–viscoplastic constitutive model involving the pressure-dependent ... -
Experimental detection of forming limit strains on samples with multiple local necks
Vysochinskiy, Dmitry; Coudert, Térence; Hopperstad, Odd Sture; Lademo, Odd-Geir; Reyes, Aase Gavina Roberg (Peer reviewed; Journal article, 2016)Sheet metal formability is traditionally described by the forming limit curve (FLC). Experimental FLCs are obtained by performing formability tests and determining failure strains. The strains are usually measured either ... -
Experimental set-up for determination of the large-strain tensile behaviour of polymers at low temperatures
Johnsen, Joakim; Grytten, Frode; Hopperstad, Odd Sture; Clausen, Arild Holm (Journal article; Peer reviewed, 2016)In this study, we present a method to determine the large-strain tensile behaviour of polymers at low temperatures using a purpose-built temperature chamber made of polycarbonate (PC). This chamber allows for several cameras ... -
An experimental study on pre-stretched double-chamber 6000-series aluminium profiles subjected to quasi-static and dynamic axial crushing
Qvale, Kristin; Hopperstad, Odd Sture; Reiso, Oddvin; Tundal, Ulf; Marioara, Calin Daniel; Børvik, Tore (Peer reviewed; Journal article, 2020)Automotive crash boxes require a material selection with strength and ductility in a balanced combination. In this work, the behaviour of double-chamber AA6063 and AA6082 aluminium profiles subjected to quasi-static and ... -
Experimental study on the formability of AA6016 sheets pre-strained by rolling
Vysochinskiy, Dmitry; Coudert, Térence; Hopperstad, Odd Sture; Lademo, Odd-Geir; Reyes, Aase Gavina Roberg (Peer reviewed; Journal article, 2017) -
First principle calculations of pressure dependent yielding in solute strengthened aluminium alloys
Frafjord, Jonas; Ringdalen, Inga Gudem; Hopperstad, Odd Sture; Holmestad, Randi; Friis, Jesper (Peer reviewed; Journal article, 2020)The pressure dependence of the yield stress in solute strengthened aluminium alloys is investigated by first principle calculations. The solute elements studied are magnesium, silicon and copper. A fixed boundary cluster ... -
Influence of constituent particles on fracture of aluminum alloys under high-triaxiality loading
Dæhli, Lars Edvard Blystad; Olufsen, Sindre Nordmark; Kristensen, Tore Andre; Børvik, Tore; Hopperstad, Odd Sture (Peer reviewed; Journal article, 2023)Single-edge notch bending tests are conducted to study the influence of constituent particles on the fracture resistance of aluminum alloys 6061, 6063, and 6110 under high-constraint loading conditions. The alloys are ... -
Influence of strain rate and temperature on the mechanical behaviour of rubber-modified polypropylene and cross-linked polyethylene
Johnsen, Joakim; Grytten, Frode; Hopperstad, Odd Sture; Clausen, Arild Holm (Journal article; Peer reviewed, 2017) -
Latent hardening and plastic anisotropy evolution in AA6060 aluminium alloy
Khadyko, Mikhail; Dumoulin, Stephane; Cailletaud, Georges; Hopperstad, Odd Sture (Peer reviewed; Journal article, 2016)The crystal plasticity theory predicts that hardening on a particular slip system and its corresponding work-hardening rate will depend on the slip activity on both this slip system and all others. The exact form of this ... -
Lattice rotations in precipitate free zones in an Al-Mg-Si alloy
Christiansen, Emil; Marioara, Calin Daniel; Marthinsen, Knut; Hopperstad, Odd Sture; Holmestad, Randi (Peer reviewed; Journal article, 2018)Scanning precession electron diffraction and automated crystal orientation mapping in a transmission electron microscope (TEM) have been applied to quantitatively study the crystal orientation of precipitate free zones ... -
Low-velocity impact behaviour and failure of stiffened steel plates
Gruben, Gaute; Sølvernes, S; Berstad, Torodd; Morin, David; Hopperstad, Odd Sture; Langseth, Magnus (Peer reviewed; Journal article, 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 ... -
A microstructure-based yield stress and work-hardening model for textured 6xxx aluminium alloys
Khadyko, Mikhail; Myhr, Ole Runar; Dumoulin, Stephane; Hopperstad, Odd Sture (Peer reviewed; Journal article, 2016)The plastic properties of an aluminium alloy are defined by its microstructure. The most important factors are the presence of alloying elements in the form of solid solution and precipitates of various sizes, and the ... -
Nano-scale characterisation of sheared β” precipitates in a deformed Al-Mg-Si alloy
Christiansen, Emil; Marioara, Calin Daniel; Holmedal, Bjørn; Hopperstad, Odd Sture; Holmestad, Randi (Journal article; Peer reviewed, 2019)This paper compares the nano-scale structure of β” precipitates in a peak-aged Al-Mg-Si alloy before and after deformation. Three complementary advanced transmission electron microscopy techniques are used to reveal the ... -
Nanoscale modelling of combined isotropic and kinematic hardening of 6000 series aluminium alloys
Myhr, Ole Runar; Børvik, Tore; Marioara, Calin Daniel; Wenner, Sigurd; Hopperstad, Odd Sture (Peer reviewed; Journal article, 2020)Kinematic hardening is incorporated into a nanoscale model for 6000 series aluminium alloys consisting of three sub-models describing in turn precipitation of hardening particles, yield strength and work hardening. The ...