Browsing NTNU Open by Author "Holmedal, Bjørn"
Now showing items 1-20 of 60
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A combined isotropic, kinematic and distortional hardening model for aluminum and steels under complex strain-path changes
Qin, Jisheng; Holmedal, Bjørn; Hopperstad, Odd Sture (Journal article; Peer reviewed, 2018)In this work, a new model is proposed for predicting stress transients caused by strain path changes. The model is formulated in stress space, where a second order tensor, i.e., the microstructure stress deviator, is used ... -
A physically-based constitutive model applied to AA6082 aluminium alloy at large strains, high strain rates and elevated temperatures
Vilamosa, Vincent; Clausen, Arild Holm; Børvik, Tore; Holmedal, Bjørn; Hopperstad, Odd Sture (Journal article; Peer reviewed, 2016)This paper presents a physically-based constitutive model applied to an AA6082 aluminium alloy subjected to large strains, high strain rates and elevated temperatures. The model accounts for thermo-elasticity, thermo-vis ... -
A TEM Study of Weakly Overaged Precipitates in AA 6082
Sulen, Olav (Master thesis, 2016)New models for modeling the material properties for aluminium alloys that can take into consideration the geometry of the needle shaped precipitates, that can be found in 6xxx alloys are being developed. The background for ... -
An explicit integration scheme for hypo-elastic viscoplastic crystal plasticity
Zhang, Kai; Holmedal, Bjørn; Dumoulin, Stephane; Hopperstad, Odd Sture (Journal article; Peer reviewed, 2014)An explicit integration scheme for rate-dependent crystal plasticity (CP) has been developed in this work. Additive decomposition of the velocity gradient tensor into lattice and plastic parts is adopted for describing the ... -
ARB-valsede laminatkompositter av AA3103 og Cu
Frydendahl, Jan Gaute (Master thesis, 2012)Laminatkompositter av plater av AA3103 aluminium + copper, samt AA3103 + C24000 messing, har blitt laget ved å anvende en prosess for akkumulert valsesveising (ARB). To forskjellige kobber/aluminium-stabler ble utsatt for ... -
Assessment of advanced Taylor models, the Taylor factor and yield-surface exponent for FCC metals
Zhang, Kai; Holmedal, Bjørn; Manik, Tomas; Saai, Afaf (Journal article; Peer reviewed, 2019)High-resolution crystal plasticity-finite element method (CPFEM) simulations are performed to provide new reference values of the Taylor factor M and the isotropic yield surface exponent for high stacking fault energy ... -
Bauschinger effect modelled by yield surface distortions
Holmedal, Bjørn (Journal article; Peer reviewed, 2019)A model for distorting the yield surface by flattening the part in the reverse of the loading direction, is suggested. As the basis for the distortion, the model applies a pair of second-order back-stress tensors of similar ... -
Bending ductility and through thickness anisotropy in 6xxx extruded profiles
Li, Yongpeng (Master thesis, 2013)6xxx aluminium alloy extruded profiles are widely used in the automotive bumper systems due to light weight, high strength and good ductility. Bending ductility dominates the behavior of bumper systems to absorb energy in ... -
Characterization and Modelling of the Microstructure and Texture Evolution In AlMgSi-Extrusions
Zhang, Kai; Marthinsen, Knut; Holmedal, Bjørn; Friis, Jesper; Pettersen, Tanja; Segatori, Antonio (Journal article, 2017)The properties and surface appearance of aluminium extrusion are critically dependent on the microstructure and texture of the extruded profiles, and the requirements with respect to these aspects may vary with applications. ... -
Characterizing hardening on annealing of cold-rolled aluminum AA3103 strips
Govindaraj, Nagaraj Vinayagam; Bjørge, Ruben; Holmedal, Bjørn (Journal article; Peer reviewed, 2013)AA3103 aluminum strips were cold rolled to various von Mises strains up to 4.7. In addition, two severely deformed conditions were obtained by one and four cycles of cold accumulated roll bonding subsequent to cold rolling ... -
Cold welding of steel and aluminum alloys - Joining processes, intermetallic phases and bond strength
Arbo, Siri Marthe (Doctoral theses at NTNU;2020:16, Doctoral thesis, 2020)Steel and aluminum are two of the most commonly used metals in today’s society and can be found everywhere, in vehicles, buildings, ships, and in most new electronic devices to name a few. Both metals have desirable ... -
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 ... -
Effect of Fe and Si content in Aluminium Alloys as a result of increased recycling: Testing of high purity Aluminium Alloys in uniaxial tension
Slagsvold, Marius (Master thesis, 2011)The recycling of aluminium from used aluminium scrap leads to an unavoidable presence of pollutions in the form of elements of various amounts. Two such elements are iron and silicon. These will always be present to some ... -
Evolution in texture and its through-thickness variations in Al-Mg-Si-extrusions: experiments and modelling
Zhang, Kai; Marthinsen, Knut; Holmedal, Bjørn; Aukrust, Trond; Segatori, Antonio (Chapter, 2018)The visual appearance and mechanical properties of aluminium alloy extrusions are strongly dependent on the microstructure and texture of the extruded profiles, where the desired microstructure and texture may depend on ... -
Experimental characterization and modeling of aluminum alloy AA3103 for complex single and double strain-path changes
Qin, Jisheng; Holmedal, Bjørn; Hopperstad, Odd Sture (Journal article; Peer reviewed, 2018)The stress-strain behavior of the aluminum alloy AA3103 subjected to single and double strain-path changes (SPCs) is studied experimentally. The experimental program includes compression-tension, tension-tension, rolling-tension ... -
Experimental Characterization and Modelling of the PLC Effect in an AlMg-Alloy
Xu, Jianbin; Holmedal, Bjørn; Hopperstad, Odd Sture; Marthinsen, Knut (Peer reviewed; Journal article, 2021)In the present work, uniaxial tension tests have been conducted to study the mechanical response of a commercial Al4.5wt%Mg alloy (AA5182). The measurements range from the strain rate of 10-4 to 100 s-1 at room temperature. ... -
Experimental investigation and modelling of strain-path changes in metals
Qin, Jisheng (Doctoral theses at NTNU;2017:287, Doctoral thesis, 2017) -
Experimental Studies of Cold Roll Bonded Aluminum Alloys
Lauvdal, Steinar (Master thesis, 2011)This master s thesis is based on experimental studies of the parameters influencing cold roll bonding (CRB) of the aluminum alloys AA1200 and AA3103,in the work hardened and annealed condition. The effect on the bond ... -
Implementasjon av en ny modell for presipitering av kuboide partikler.
Osmundsen, Elisa Ariane (Master thesis, 2013)Målet med dette prosjektet var å implementere en modell for å beskrive hvordan distribusjonen av presipitater endres underveis ved presipitering i aluminiumslegeringer, som kan brukes til alle sideforhold av presipitatnåler. ... -
Influence of dispersoids on grain subdivision and texture evolution in aluminium alloys during cold rolling
Zhao, Qinglong; Holmedal, Bjørn (Journal article, 2014)Al-Mn alloys containing similar amounts of solutes but various dispersoid densities were cold rolled. The grain subdivision and micro-texture were examined by electron backscatter diffraction and orientation imaging ...