Blar i NTNU Open på forfatter "Leira, Bernt Johan"
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Assessment of Hull Response due to Impact from Falling Object
Bergstad, Andreas (Master thesis, 2014)The present study assesses ship hull response of a platform supply vessel due to impact from falling objects. This is carried out primarily by investigating the critical energy absorption and localised deformation to ... -
Assessment of methods for short-term analysis of riser collision probability
Fu, Ping; Leira, Bernt Johan; Myrhaug, Dag; Chai, Wei (Peer reviewed; Journal article, 2021)Reliability- and performance-based design of a riser cluster requires an accurate estimation of the extreme values of the stochastic relative distance between the risers during a given time duration. This study presents a ... -
Assessment of Methods for Short-Term Extreme Value Analysis of Riser Collision
Fu, Ping; Leira, Bernt Johan; Myrhaug, Dag (Chapter, 2018)Risers are commonly arranged as clusters with relatively small spacing due to economic necessity. As a consequence, collision between risers becomes an essential problem. This study presents a comprehensive assessment of ... -
Assessment of structural requirements related to LNG fuel tanks
Aga, Halvor Larsson (Master thesis, 2013)This thesis considers collision between ships, and the structural resistance of the struckship with the aim to minimize the indentation into the ship side.First it gives a background in ship collision analysis, different ... -
Bayesian Damage Prediction on Berm Breakwaters in the Arctic
Pontiki, Maria (Master thesis, 2018)A model for the computation of failure probabilities on partly reshaping mass-armored berm breakwaters in Arctic is presented. The model consists a reliable tool for the design of port structures in the rapidly changing ... -
A benchmarking exercise for environmental contours
Haselsteiner, Andreas F.; Coe, Ryan G.; Manuel, Lance; Chai, Wei; Leira, Bernt Johan; Clarindo, Guilherme; Soares, Carlos Guedes; Hannesdóttir, Ásta; Dimitrov, Nikolay; Sander, Aljoscha; Ohlendorf, Jan-Hendrik; Thoben, Klaus-Dieter; Hauteclocque, Guillaume de; Mackay, Ed; Jonathan, Philip; Qiao, Chi; Myers, Andrew; Rode, Anna; Hildebrandt, Arndt; Schmidt, Boso; Vanem, Erik; Huseby, Arne Bang (Peer reviewed; Journal article, 2021)Environmental contours are used to simplify the process of design response analysis. A wide variety of contour methods exist; however, there have been a very limited number of comparisons of these methods to date. This ... -
Code-to-Code Verification of End-Anchored Floating Bridge Global Analysis
Viuff, Thomas; Xiang, Xu; Leira, Bernt Johan; Øiseth, Ole (Chapter, 2018)A code-to-code comparison of the dynamic characteristics of an end-anchored floating pontoon bridge is presented for two commercial software commonly used in the offshore industry, i.e. SIMO-RIFLEX and ORCAFLEX. Furthermore, ... -
Comparative Analysis of Umbilical Pull-in through J-tubes by Detailed Models and Simplified Methods
Berntsen, Martine (Master thesis, 2015)Design and installation of offshore structures and subsea pipelines requires knowledge about loads that will affect the equipment during the installation process and estimates of the load effects during the lifetime of the ... -
Comparative Study of the Path Integration Method and the Stochastic Averaging Method for Nonlinear Roll Motion in Random Beam Seas
Chai, Wei; Dostal, Leo; Næss, Arvid; Leira, Bernt Johan (Journal article; Peer reviewed, 2017)In this work, the path integration method and the energy-based stochastic averaging method are introduced in order to study the stochastic responses of ship roll motion in random beam seas. Based on the Markov property of ... -
Comparative study on the dynamic response of a Spar type buoy and a Sevan type cylinder floating production unit
Odden, Eirik Hollerud (Master thesis, 2012)Comparative study on the dynamic response of a Spar type buoy and a Sevan type cylinder floating production unit -
Comparison between Measured and Calculated Riser Response
Stange, Ivar (Master thesis, 2012)Well intervention operations can inflict large strains on a wellhead. The seabed in the North Sea is very rigid up to the point where the sea water meets the mud or sand. This is one of the reasons why wellheads operating ... -
A Comparison of Methods for Estimation of Fatigue and Extreme Mooring Response for a Floating Spar Wind Turbine
Bjørnsen, Gaute Sjeggestad (Master thesis, 2015)Hywind Demo is one of the worlds first floating offshore wind turbines. It is operated by Statoil and located off the coast of Karmøy in Norway. The substructure is a spar shaped hull, and it is moored with catenary mooring ... -
Concept Study and Analysis of a Constant Buoyancy System for a Floating Single Column Platform
Midtbust, Sondre Stang (Master thesis, 2018)The main objective of this thesis is to study a new platform concept which utilizes a submerged air volume for maintaining constant buoyancy. The work is motivated by the possible application as pontoons for floating bridges ... -
Concept Study and Analysis of a Floating Bridge
Brede, Heidi (Master thesis, 2017)A floating bridge is a structure carrying traffic across a body of water and whose supports floats on the surface. The history of the floating bridge goes as far back as around 2000 BCE, when their use was mainly military. ... -
A Concept Study of a Pre-tensioned S-shaped Pontoon Bridge with Submerged Floating Twin-Tubes
Fløgum, Benedicte Elise (Master thesis, 2018)The marine bridge differs from a regular bridge by using buoyancy units, often so-called pontoons, to obtain vertical equilibrium instead of rigid foundations. The term may include floating bridges, such as typical pontoon ... -
Consolidated layer thickness in probabilistic simulation of first-year ice ridges
Samardžija, Ilija; Høyland, Knut Vilhelm; Leira, Bernt Johan; Næss, Arvid (Peer reviewed; Journal article, 2023)This research study focuses on resolving the issue of sparse data and information required for the probabilistic assessment of ice ridge loads in offshore structures in Arctic regions. The study introduces the consolidated ... -
Constructive Alignment in Science and Engineering: From Principle to Practice
Gynnild, Vidar; Leira, Bernt Johan; Myrhaug, Dag; Holmedal, Lars Erik; Mossige, Jon Coll (Journal article; Peer reviewed, 2019)This paper reports on an action research study on task design and constructive alignment in an optional module at the Norwegian University of Science and Technology. While students appreciated the two professors’ teaching, ... -
Contour Methods for Deepwater Riser Systems
Øyri, Torstein (Master thesis, 2014)This is a master thesis about environmental contour line methods for extreme responseanalysis of deep water marine riser system. The marine riser systems playsan important part of oil and gas exploration and production ... -
Contour Methods for Estimation of Multi-dimensional Extreme Riser Response
Lindstad, Halvor Borgen (Master thesis, 2013)The aim of this thesis is to investigate the extreme response of a flexible riser.A full long term analysis is usually carried out to find the response with a givenreturn period in years, which is a useful quantity in ... -
Coupled Analysis of a Moored Sevan Hull by the use of OrcaFlex
Hanssen, Erik Byholt (Master thesis, 2013)Offshore activity related to the search of energy in terms of hydrocarbons is taking place at increasing water depths. In deeper water, the effects on the floater motion from the mooring and riser systems increase ...