Browsing NTNU Open by Author "Holmedal, Bjørn"
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Influence of thermomechanical processing sequence on properties of AA6082-IF steel cold roll bonded composite sheet
Arbo, Siri Marthe; Bergh, Tina; Solhaug, Harald; Westermann, Ida; Holmedal, Bjørn (Journal article; Peer reviewed, 2018)Cold roll bonded tri-layered composites consisting of AA6082 and IF steel have been produced. The goal was to find the optimal sequence of solutionizing, aging and rolling, for obtaining good bond strength and at the same ... -
Investigation of a Non-Associated Flow Rule Incorporating Corner Effects and Comparison with an Elastoplastic Crystal Plasticity Model
Gjesdal, Bjørnar (Master thesis, 2019)Den konvensjonelle assosierte flyteregelen, brukt i kontinuums plastisitetsmodeller, er uegnet til prediksjon av flytinstabiliteter i tynne plater under biaksiell last og plastisk bukling ved bifurkasjonsanalyse. Teorien ... -
Investigation of bond strength and intermetallic phases in roll bonded steel-aluminium laminates at 150oC - Including the use of nickel interlayers
Sverdrup, Erlend (Master thesis, 2018)This master's thesis investigates intermetallic growth and metallurgical bonding in cold roll-bonded steel-aluminium laminates. Commercially pure AA1080 aluminium alloy have been roll-bonded with two different steel types, ... -
Layer continuity in accumulative roll bonding of dissimilar material combinations
Govindaraj, Nagaraj Vinayagam; Frydendahl, Jan Gaute; Holmedal, Bjørn (Journal article; Peer reviewed, 2013)Strips were made by accumulative roll bonding of up to 64 alternating layers of an AA3103 alloy and either commercial purity copper or CuZn20 brass as the second type of layer. With increasing number of accumulative roll ... -
Low Cycle Fatigue of Extruded and Cast Aluminium Alloy 6082
Reinton, Tone Elise (Master thesis, 2017)The objective of the research is to determine the differences between the low cycle fatigue properties of an extruded and cast treatments of AA6082-T6 used as the forging billet in the production of a car suspension arm. ... -
Modeling over-ageing in Al-Mg-Si alloys by a multi-phase CALPHAD-coupled Kampmann-Wagner Numerical model
Du, Qiang; Tang, Kai; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Holmedal, Bjørn; Holmestad, Randi (Journal article, 2017)The formation of the equilibrium precipitation phase during ageing treatment of Al-Mg-Si alloys is preceded by a series of metastable phases. Given longer ageing time, higher ageing temperature or elevated temperature ... -
Modeling strain-path changes in aluminum and steel
Qin, Jisheng; Holmedal, Bjørn; Zhang, Kai; Hopperstad, Odd Sture (Journal article, 2017)The present paper evaluates two phenomenological plasticity models which account for the influence of strain-path change (SPC) on the stress-strain behavior. The HAH model (Barlat et al., 2014) is modified to capture SPC ... -
Modelling and experimental validation of microstructure evolution during the cooling stage of homogenization heat treatment of Al-Mg-Si alloys
Du, Qiang; Jia, Lina; Tang, Kai; Holmedal, Bjørn (Peer reviewed, 2018)A CALPHAD-coupled multi-component multi-phase Kampmann–Wagner Numerical modelling framework has been adapted and coupled with a homogenization model to predict the competitive nucleation and growth of multi-sized ... -
Modelling of strain-path transients in commercially pure aluminium
Qin, Jisheng; Holmedal, Bjørn; Hopperstad, Odd Sture (Journal article, 2017)In the current work, the recently proposed homogeneous anisotropic hardening (HAH) model, featuring a distorted yield surface, is applied to commercially pure aluminium. A dislocation-based hardening rule is incorporated ... -
Modelling work hardening of aluminium alloys containing dispersoids
Zhao, Qinglong; Holmedal, Bjørn (Journal article; Peer reviewed, 2013)The influence of dispersoids on tensile deformation behaviour has been studied by comparison of aluminium alloys containing different dispersoid densities. It was found that a fine dispersion of non-shearable particles led ... -
Multi-level modelling of mechanical anisotropy of commercial pure aluminium plate: Crystal plasticity models, advanced yield functions and parameter identification
Zhang, Kai; Holmedal, Bjørn; Hopperstad, Odd Sture; Dumoulin, Stephane; Gawad, Jerzy; Van Bael, Albert; Van Houtte, P (Journal article; Peer reviewed, 2015)The mechanical anisotropy of an AA1050 aluminium plate is studied by the use of five crystal plasticity models and two advanced yield functions. In-plane uniaxial tension properties of the plate were predicted by 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 ... -
Permanent Effect of a Cryogenic Spill on Fracture Properties of Carbon Steel
Keseler, Hanne (Master thesis, 2015)In this work, the permanent effect of a cryogenic spill on the fracture properties of carbon steel was investigated. The experimental work consisted of two main parts. The first part was the examination of a plate of ... -
Permanent effect of a cryogenic spill on fracture properties of structural steels
Keseler, Hanne; Westermann, Ida; Kandukuri, Sastry Yagnanna; Nøkleby, John Olav; Holmedal, Bjørn (Journal article; Peer reviewed, 2015)Fracture analysis of a standard construction steel platform deck, which had been exposed to a liquid nitrogen spill, showed that the brittle fracture started at a flaw in the weld as a consequence of low-temperature ... -
Precipitation and strengthening modeling for disk-shaped particles in aluminum alloys: Size distribution considered
Li, Yue; Holmedal, Bjørn; Li, Hongxiang; Zhuang, Linzhong; Zhang, Jishan; Du, Qiang (Journal article, 2018)For an ICME (Integrated Computational Material Engineering) modeling framework used for the age-hardening aluminum alloy design and heat treatment parameters optimization, it is critical to take into account the geometric ... -
Precipitation of Non-Spherical Particles in Aluminum Alloys Part I: Generalization of the Kampmann–Wagner Numerical Model
Holmedal, Bjørn; Osmundsen, Elisa; Du, Qiang (Journal article, 2015)Particles precipitated during aging treatments often have non-spherical shapes, e.g., needles or plates, while in the classical Kampmann–Wagner Numerical (KWN) precipitation model, it is assumed that the particles are of ... -
Precipitation, strength and work hardening of age hardened aluminium alloys
Ryen, Øyvind; Holmedal, Bjørn; Marthinsen, Knut; Furu, Trond (Journal article; Peer reviewed, 2015)The strength and work hardening of age hardened AA6063 and AA6082 alloys have been investigated in terms of a detailed characterization of precipitate and dislocation structures obtained by TEM and SEM. Tensile and compression ... -
Press Form Hardening of Aluminium - The influence of hot forming, quench interruption and direct artificial aging on the mechanical properties of AA6082
Myrold, Benedikte Jørgensen (Master thesis, 2018)The automotive industry is in need of new lightweight solutions to meet stricter regulations regarding reduction in greenhouse gas emissions. Replacing steel components with age-hardenable high-strength aluminium alloys ... -
Relationship between Al-Ni intermetallic Phases and Bond Strength in Roll Bonded Steel-Aluminum Composites with Nickel Interlayers
Arbo, Siri Marthe; Bergh, Tina; Holmedal, Bjørn; Vullum, Per Erik; Westermann, Ida (Journal article; Peer reviewed, 2019)In this work, the interface characteristics and resulting bond strength were investigated for roll bonded steel-aluminum composites with nickel interlayers, both after rolling and after post-rolling heat treatments at 400 ... -
Spin and vorticity with vanishing rigid-body rotation during shear in continuum mechanics
Holmedal, Bjørn (Journal article; Peer reviewed, 2020)A long-standing challenge in continuum mechanics has been how to separate shear deformation and corresponding shape changes from the rotation of a continuum. This can be obtained by a new decomposition of the spin tensor, ...