Browsing NTNU Open by Author "Ås, Sigmund Kyrre"
Now showing items 1-14 of 14
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A comparison of physical and numerical modeling of homogenous isotropic propeller blades
Savio, Luca; Sileo, Lucia; Ås, Sigmund Kyrre (Journal article; Peer reviewed, 2020)Results of the fluid-structure co-simulations that were carried out as part of the FleksProp project are presented. The FleksProp project aims to establish better design procedures that take into account the hydroelastic ... -
A gradient-based multiaxial criterion for fatigue crack initiation prediction in components with surface roughness
Skallerud, Bjørn Helge; Ås, Sigmund Kyrre; Ottosen, Niels S. (Journal article, 2018)The current study presents methods to predict the governing crack initiation site and fatigue crack initiation life of components with surface roughness. The surface topography is measured with white light interferometry ... -
Assessment of Pipeline Integrity after Trawling Impact by Investigating Dent with Gouge
Eliassen, Agnes Karin (Master thesis, 2016)Mechanical damage from trawling gear interference amongst others cause a significant amount of damage to pipelines. The present study has done a review of current standards and recommended practise for assessment methods ... -
Crystal plasticity modeling of microstructure influence on fatigue crack initiation in extruded Al6082-T6 with surface irregularities
Hallberg, Håkan; Ås, Sigmund Kyrre; Skallerud, Bjørn Helge (Journal article, 2018)The influence of surface roughness and microstructure heterogeneities in the vicinity of macroscopic stress concentrations are investigated by crystal plasticity simulations. It is shown that in the extruded Al6082-T6 alloy ... -
Digital image correlation for continuous mapping of fatigue crack initiation sites on corroded surface from offshore mooring chain
Qvale, Paul; P. Zarandi, Ershad; Ås, Sigmund Kyrre; Skallerud, Bjørn Helge (Peer reviewed; Journal article, 2021)The full-field digital image correlation (DIC) technique was used to identify crack initiation and early crack growth on irregular, corroded surfaces from offshore mooring chain. Finite element analysis was paired with the ... -
Isogeometric Phase-Field Methods for Modeling Fracture in Shell Structures
Proserpio, Davide (Doctoral theses at NTNU;2021:87, Doctoral thesis, 2021)The simulation of the fracture of engineering structures is a challenging topic that requires accurate and efficient numerical models. This thesis focuses on the modeling of brittle and ductile fracture in thin shell structures ... -
Material Parameter Identification Using Artificial Neural Networks and Genetic Algorithm
Midtgarden, Olav (Master thesis, 2018)Finite element method (FEM) simulations are widely used to perform structural analysis. To ensure that the results obtained from the simulations are realistic it is crucial to have a material model that is as close to ... -
Monitoring of Fatigue Damage for Offshore Wind Turbine Foundations - Investigating Operation Strain Estimation Techniques
Norbruis, Joris Obbe (Master thesis, 2017)A global focus on the shift to renewable energy has introduced international targets for sustainable energy production, which have strongly increased the interest in offshore wind turbines (OWT s). In order to make offshore ... -
Non-linear Irregular Wave Impact on Monopile Structures
Schöpfer, Philipp (Master thesis, 2016)This Master Thesis deals with non-linear wave impacts on monopile structures by introducing a potential flow solver named OceanWave3D (OCW3D) for simulating free surface waves and their kinematics under engineering ... -
Out of Plane Bending of Mooring Chains - Finite Element Analysis of a 7-link Model
Berthelsen, Katarina (Master thesis, 2017)This master's thesis is an investigation of out of plane bending (OPB) as a failure mode connected to the upper chain section of offshore mooring lines. A comprehensive literature study was done to present the OPB mechanism, ... -
Pipeline damage assessment after trawling impact
Ellingsen, Sondre Lydvo (Master thesis, 2018)Bulking av subsea-rørledning på grunn av kollisjon med trålere kan ha en betydelig effekt på den gjenverende utmattings-levetiden til røret. Kriterie som benyttes til å avgjøre om et rør et sikkert etter bulking har innebyg ... -
Pipeline Integrity Assessment of Dent with Gouge after Trawling Impact
Aadal, Adrian Haugsand (Master thesis, 2017)Damage to pipelines from interaction with trawler-gear affects the long-term integrity of the pipeline, and interference from trawling-equipment on subsea pipelines is a relatively common occurrence. This thesis looks on ... -
Towards Remaining Life Assessment by use of Conditional Adversarial Networks
Pettersen, Håkon Kvalvåg (Master thesis, 2021)Statistikk viser at fler-tallige tap av forankringsliner har skjedd tidlig i den designede levetiden. Forankringsliner av kjetting var ansvarlige for opptil 50 % av alle tap, hvor utmatting var en av hoved°arsakene for ... -
Towards Remaining Life Assessment Using Machine Learning
Heien, Henrik (Master thesis, 2021)Brudd i ankerkjettinger grunnet korrosjon og utmatting er et problem offshorenæringen møter. Brudd i flere kjettinger i permanent oppankrede systemer har vist seg å ha en årlig frekvens på omtrent 3 x 10^-3 og de fleste ...