Blar i NTNU Open på forfatter "Johnsen, Joakim"
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A nano-scale material model applied in finite element analysis of aluminium plates under impact loading
Johnsen, Joakim; Holmen, Jens Kristian; Myhr, Ole Runar; Hopperstad, Odd Sture; Børvik, Tore (Journal article, 2013)Finite element simulations of AA6070 aluminium plates struck by ogival-nose projectiles are performed. The aluminium plates are 20 mm thick and heat treated to temper O, T4, T6 and T7. A nano-scale material model, consisting ... -
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)In this study, a thermo-elasto-viscoplastic model is developed for a low density cross-linked polyethylene (XLPE) in an attempt to describe the combined effects of temperature and strain rate on the stress-strain response ... -
Cylindrical cavity expansion approximations using different constitutive models for the target material
Johnsen, Joakim; Holmen, Jens Kristian; Warren, Thomas L.; Børvik, Tore (Journal article; Peer reviewed, 2017)In this article, we investigate the results obtained using different constitutive models for the solution of the cylindrical cavity expansion problem under plane strain conditions. The cylindrical cavity expansion solutions ... -
Effects of heat treatment on the ballistic properties of AA6070 aluminium alloy
Holmen, Jens Kristian; Johnsen, Joakim; Jupp, S; Hopperstad, Odd Sture; Børvik, Tore (Journal article; Peer reviewed, 2013)The ballistic properties of the aluminium alloy AA6070 in different tempers are studied, using target plates of 20 mm thickness in tempers O (annealed), T4 (naturally aged), T6 (peak strength) and T7 (overaged). The ... -
Effects of Heat Treatment on the Ballistic Properties of AA6070 Aluminium Plates
Holmen, Jens Kristian; Johnsen, Joakim (Master thesis, 2012)The thesis includes a summary of important theory in the fields of impact engineering and plasticity theory, and a literature study is carried out on aluminium designations, alloying and heat treatment. The true stress-strain ... -
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 ... -
Impact of stress triaxiality, strain rate, and temperature on the mechanical response and morphology of PVDF
Hund, Jonas; Granum, Henrik Møgster; Olufsen, Sindre Nordmark; Holmström, Petter Henrik; Johnsen, Joakim; Clausen, Arild Holm (Journal article; Peer reviewed, 2022) -
Influence of fragmentation on the capacity of aluminum alloy plates subjected to ballistic impact
Holmen, Jens Kristian; Johnsen, Joakim; Hopperstad, Odd Sture; Børvik, Tore (Journal article; Peer reviewed, 2016)In this paper, the perforation resistance of 20 mm thick aluminum plates subjected to moderate velocity impacts is examined experimentally and numerically. Plates made of four different tempers of aluminum alloy AA6070 ... -
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)In the present work, we investigate the effects of strain rate (e˙=0.01 s−1, 0.1 s−1, and 1.0 s−1) and low temperature (T=−30 °C, −15 °C, 0 °C, and 25 °C) on the mechanical behaviour in tension and compression of two ... -
Solution for the Dynamic Elastically Compressible Power-Law Strain Hardening Cylindrical Cavity-Expansion Problem
Warren, Tom; Johnsen, Joakim; Kristoffersen, Martin; Børvik, Tore (Journal article; Peer reviewed, 2022) -
Thermomechanical behaviour of semi-crystalline polymers: experiments, modelling and simulation
Johnsen, Joakim (Doctoral theses at NTNU;2017:317, Doctoral thesis, 2017)This work presents experimental investigations on two semi-crystalline materials: a rubbermodified polypropylene (PP) and a cross-linked low density polyethylene (XLPE). Uniaxial tension and compression tests were performed ...