Blar i NTNU Open på forfatter "Hopperstad, Odd Sture"
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Anisotropic tensile behaviour of short glass-fibre reinforced polyamide-6
Holmström, Petter Henrik; Hopperstad, Odd Sture; Clausen, Arild Holm (Peer reviewed; Journal article, 2020)This paper presents an experimental investigation of injection-moulded short glass-fibre reinforced polyamide-6 reinforced with 0 wt.%, 15 wt.% and 30 wt.% fibres. The fibre orientation distributions are characterized by ... -
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)This paper investigates the influence of plastic anisotropy on the tensile ductility of a high-strength aluminium alloy. To this end, finite element simulations of smooth and notched tension tests in different material ... -
Anisotropic yield surfaces of additively manufactured metals simulated with crystal plasticity
Somlo, Kinga; Frodal, Bjørn Håkon; Funch, C.V.; Poulios, K.; Winther, G.; Hopperstad, Odd Sture; Børvik, Tore; Niordson, C.F. (Peer reviewed; Journal article, 2022)The mechanical anisotropy created by additive manufacturing (AM) is not yet fully understood and can depend on many factors, such as powder material, manufacturing technology and printing parameters. In this work, the ... -
Assessment of yield and fracture criteria using shear and bending tests
Reyes, Aase Gavina Roberg; Eriksson, Magnus; Lademo, Odd-Geir; Hopperstad, Odd Sture; Langseth, Magnus (Journal article; Peer reviewed, 2009)This article deals with the calibration of a fracture criterion that has been implemented in a material model in LS-DYNA. The failure process in thin-walled metallic materials is complex and often due to interaction between ... -
ATLAS of yield surfaces for strongly textured FCC polycrystals
Dumoulin, Stephane; Coudert, Térence; Hopperstad, Odd Sture (Journal article; Peer reviewed, 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 ... -
Ballistic impact of layered and case-hardened steel plates
Holmen, Jens Kristian; Solberg, Jan Ketil; Hopperstad, Odd Sture; Børvik, Tore (Journal article; Peer reviewed, 2017)We investigated the ballistic resistance of hot-rolled structural steel plates with a nominal yield stress of 355 MPa in this study. Ballistic tests were conducted with 7.62mm armor piercing bullets on monolithic and ... -
Ballistic impact of structural steels at low temperatures
Holmen, Jens Kristian; Thomesen, Susanne; Perez-Martin, Maria Jesus; Hopperstad, Odd Sture; Børvik, Tore (Peer reviewed; Journal article, 2022)Steels are usually stronger at low temperatures than at high temperatures. But low temperatures are, particularly in combination with high strain rates and high stress triaxiality ratios, known to cause embrittlement. The ... -
Ballistic Perforation of Surface Hardened Mild Steel Plates
Thorsen, Henrik; Orthe, Erlend (Master thesis, 2014)The main objective with this thesis was to investigate experimentally and numerically the effect surface hardening has on the ballistic properties of monolithic and laminated mild steel plates. 300x300 mm^2 plates of ... -
Behavior of PVC and HDPE under highly triaxial stress states: An experimental and numerical study
Ognedal, Anne Serine; Clausen, Arild Holm; Dahlen, Anfrid; Hopperstad, Odd Sture (Journal article; Peer reviewed, 2014)This paper addresses the deformation of axisymmetric tensile bars, made of mineral-filled PVC and HDPE, with and without pre-machined notch. The purpose of the study is both to investigate the mechanical behavior under ... -
Behaviour of Al-Mg-Si alloys at a wide range of temperatures and strain rates
Vilamosa, Vincent; Clausen, Arild Holm; Børvik, Tore; Skjervold, SR; Hopperstad, Odd Sture (Journal article; Peer reviewed, 2015)The thermo-mechanical behaviour in tension of three as-cast and homogenized Al-Mg-Si alloys, distinguished by their Mg and Si content, was investigated at a wide range of strains (the entire deformation process up to ... -
Cack propagation in aluminium alloy plates: experiments, modelling and simulation
Blytt, Aslak Magdalon; Sundt, Sander (Master thesis, 2021)Denne masteroppgaven har studert sprekkpropagering i 1.5mm tykke plater av aluminiumslegeringen AA6016 utsatt for kvasisstatisk- og dynamisk last. Forsøkene har blitt modellert ved bruk av en FEA og en Gurson-Tvergaard-needleman ... -
Calibration of the modified Mohr-Coulomb fracture model by use of localization analyses for three tempers of an AA6016 aluminium alloy
Granum, Henrik; Morin, David; Børvik, Tore; Hopperstad, Odd Sture (Peer reviewed; Journal article, 2021)This paper presents a novel calibration procedure of the modified Mohr-Coulomb (MMC) fracture model by use of localization analyses and applies it for three tempers of an AA6016 aluminium alloy. The localization analyses ... -
Characterization and modeling of the mechanical behavior of polymer foam
Morton, Daniel Thor (Doctoral theses at NTNU;2021:173, Doctoral thesis, 2021)Polymer foams are often used in safety applications, for example in pedestrian impact protection where a polymer foam bumper can increase pedestrian safety in the event of an accident. Application of this type of material ... -
Characterization of High Carbon Steel C68 at Elevated Temperatures and Different Strain Rates
Vautrot, M; Balland, P; Hopperstad, Odd Sture; Tabourot, L; Raujol-Veille, J; Toussaint, F. (Journal article; Peer reviewed, 2012)This paper presents high-temperature tensile testing. This method is used to characterize the mechanical behaviour of a high-carbon steel C68 at temperatures up to 720°C. Samples are heated by an induction system controlled ... -
Constitutive modeling of a graded porous polymer based on X-ray computed tomography
Vestrum, Ole; Dæhli, Lars Edvard Blystad; Hopperstad, Odd Sture; Børvik, Tore (Peer reviewed; Journal article, 2020)This work focuses on the constitutive modeling of a graded porous polymer pipeline coating based on X-ray micro computed tomography (XRMCT). Previous work has revealed that finite element (FE) models generated from XRMCT ... -
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 ... -
Crack propagation in aluminium alloy plates: experiments, modelling and simulation
Blytt, Aslak Magdalon; Sundt, Sander (Master thesis, 2021)Denne masteroppgaven har studert sprekkpropagering i 1.5mm tykke plater av aluminiumslegeringen AA6016 utsatt for kvasisstatisk- og dynamisk last. Forsøkene har blitt modellert ved bruk av en FEA og en Gurson-Tvergaard-needleman ... -
Crash behavior of obliquely loaded aluminum extrusions
Reyes, Aase Gavina Roberg; Langseth, Magnus; Hopperstad, Odd Sture (Chapter, 2002)The energy absorbing capability of obliquely loaded aluminum extrusions was studied through quasi-static experiments. Square aluminum columns in alloy AA6060 were clamped at one end and oblique load conditions were realized ... -
Crashworthiness of aluminum extrusions subjected to oblique loading: experiments and numerical analyses
Reyes, Aase Gavina Roberg; Langseth, Magnus; Hopperstad, Odd Sture (Journal article; Peer reviewed, 2002)Oblique loading was studied through quasi-static experiments and numerical simulations. The behavior of square aluminum columns in alloy AA6060 subjected to quasi-static oblique loading was investigated experimentally for ... -
Crystal plasticity finite element simulations of pure bending of aluminium alloy AA7108
Saai, Afaf; Westermann, Ida; Dumoulin, Stephane; Hopperstad, Odd Sture (Journal article; Peer reviewed, 2015)The crystal plasticity finite element method (CP-FEM) is used to investigate the influence of microstructure on the bending behaviour of the heat treatable aluminium alloy AA7108. The study comprises two materials obtained ...