Blar i Institutt for marin teknikk på utgivelsesdato
Viser treff 601-620 av 3421
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Approaches for assessment of weld fatigue and verification of the effective notch stress approach
(Master thesis, 2014)Fatigue of welded structures is commonly assessed in three ways. These are the nominal stress-, the structural hot spot- and the effective notch stress approach. As the applicability of the approaches differs, these ... -
Dynamic Positioning in Extreme Sea States: Improving Operability Using Hybrid Design Methods
(Master thesis, 2014)This thesis investigates the performance of high-level hybrid dynamic positioning (DP) algorithms in extreme environmental conditions. A vessel in DP uses the thrusters as the sole means of keeping position in wind, waves ... -
Safe and efficient operation and maintenance of offshore wind farms
(Doktoravhandlinger ved NTNU, 1503-8181; 2014:70, Doctoral thesis, 2014)This PhD work has been carried out when early experience is obtained from the first offshore wind energy projects and new projects with large capacity are in preparation. The importance and challenges of operation and ... -
Damage Assessment of Sevan FPSO Subjected to Impacts From Shuttle Tankers
(Master thesis, 2014)Platform-ship collisions are fortunately rare events, but as the development of the offshore and oil industry and the gradually frequently used offloading operation, accidents become more and more frequent. The consequences ... -
The buckling resistance of structures subjected to impulsive type actions
(Master thesis, 2014)The behavior and resistance of structural components subjected to impulsive type loads is investigated. An increased insight into dynamic buckling is achieved by performing a literature study, together with analyses on ... -
Kombinert modelbasert og sensorbasert observer for undervannsfartøy
(Master thesis, 2014)Denne master-oppgaven omhandler arbeidet med å kombinere to ulike typer observere på en slik måte at kombinasjonen av disse to gir et bedre resultat enn det de to observerene klarer hver for seg. De to observerene er den ... -
Optimalisering av søkemønstre for bruk ved SAR-operasjoner i kalde omgivelser
(Master thesis, 2014)Den økte aktiviteten i nordområdene og rundt Arktis gir nye utfordringer hva gjelder beredskap. Fartøy og aktører blir i disse store områdene pålagt å kunne håndtere krisesituasjoner i større grad på egenhånd enn andre ... -
Ringing loads on tension leg platform wind turbines
(Journal article; Peer reviewed, 2014)The present work identifies realistic wave (and associated wind) conditions which could induce ringing responses in tension leg platform wind turbines (TLPWTs). The simulation results show the importance of ringing forces, ... -
A harmonic polynomial cell (HPC) method for 3D Laplace equation with application in marine hydrodynamics
(Journal article; Peer reviewed, 2014)We propose a new efficient and accurate numerical method based on harmonic polynomials to solve boundary value problems governed by 3D Laplace equation. The computational domain is discretized by overlapping cells. Within ... -
Efficient Response Simulation Strategies for Jacket-based Offshore Wind Turbines - An integrated approach combining model reduction and nonlinear irregular wave theory
(Master thesis, 2014)The offshore wind industry has been growing exponentially over the last two decades, thereby establishing itself as one of the most promising alternative energy sources. Technological developments are required to reach ... -
Assessment of Uncertainties in Estimated Wellhead Fatigue
(Master thesis, 2014)During subsea drilling, the motions of the Mobile Offshore Drilling Unit (MODU) and riser cause cyclic bending moments on the wellhead. This may lead to fatigue failure of the component, which can have severe consequences, ... -
Life Cycle Cost Comparison Study - An analysis of a LNG ferry's performance and potential for improvement
(Master thesis, 2014)A life cycle cost comparison study between a newly built LNG ferry and a 21 year old conventional ferry was carried out in this study. The objective was to study the LNG vessel s cost effectiveness compared to an equivalent ... -
Reducing the probability of ship grounding: Which measure to undertake?
(Journal article; Peer reviewed, 2014)The analytic hierarchy process has been used to elicit the knowledge of maritime transport stakeholders, such as seafarers, authorities, insurers and academics, regarding human factors and risk-reducing measures for ship ... -
Analysis of lifting operation of a monopile for an offshore wind turbine considering vessel shielding effects
(Journal article; Peer reviewed, 2014)This study addresses numerical simulations of the lifting operation of a monopile for an offshore wind turbine with a focus on the lowering process. A numerical model of the coupled system of the monopile and vessel is ... -
Topics in dynamic positioning: System identification, GNSS and MRU lever arm estimation, and hybrid integral action
(Master thesis, 2014)This thesis consists of three main parts. The first part of the master thesis looks at the identification of thruster dynamics and low speed ship dynamics. The relevant parameters identified are time constants and time ... -
Fatigue Study of Copper Conductors
(Master thesis, 2014)This master thesis was carried out during the spring semester of 2014 at Department of Marine Technology in Norwegian University of Science and Technology. It was a continuous work of the master project during autumn ... -
Feasibility Study on Active Wave Compensation of ROV - Modelling, Analysis and Simulation
(Master thesis, 2014)The aquaculture industry is using remotely operated vehicles (ROVs) for maintenance tasks on fish farms. These tasks include, among others, washing of the netpen and visual inspections. These are tedious tasks, and it would ... -
Dynamic buckling of marine structures
(Master thesis, 2014)In this report the buckling resistance of marine structures when dynamic effects is important is investigated. A review of the governing theory is presented for both beam and plates. A sample of the different ways of solving ... -
A Unified Framework for Fault Detection and Diagnosis Using Particle Filter
(Journal article; Peer reviewed, 2014)In this paper, a particle filter (PF) based fault detection and diagnosis framework is proposed. A system with possible faults is modeled as a group of hidden Markov models representing the system in fault-free mode and ... -
Damage Identification of an Offshore Wind Turbine Jacket Support Structure
(Master thesis, 2014)Due to the variable and stochastic offshore environment, offshore wind turbines are prone to fatigue. Fatigue damage usually occurs as cracks and is an important indicator of the structure's condition and the remaining ...