Browsing NTNU Open by Author "Haver, Sverre Kristian"
Now showing items 1-12 of 12
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Adequate linearization scheme for a jack-up in order to obtain sufficiently accurate fatigue assessments using a linear stochastic fatigue analyses
Karlsson, Marius Tveit (Master thesis, 2017)Different techniques for linearizing the response of drag dominated structures is in this work inspected in terms of fatigue damage. To establish reference response characteristics, time domain simulations are carried out. ... -
Assessing some statistical and physical modelling uncertainties of extreme responses for monopile-based offshore wind turbines, using metocean contours
Katsikogiannis, George; Haver, Sverre Kristian; Bachynski-Polic, Erin Elizabeth (Peer reviewed; Journal article, 2024)This study examines the influence of probabilistic models for wave parameters in the joint environmental model and hydrodynamic/soil models on extreme mudline bending moments for monopile-based wind turbines at representative ... -
Assessment of Necessary Air Gap of Semi-Submersible Accounting for Simultaneous Occurrence of Wind, Wind Sea and Swell Sea
Vikenes, Ole Kristian (Master thesis, 2018)The objective of this thesis is to estimate the necessary air gap of a semi-submersible in the Northern North Sea accounting for simultaneous occurrence of wind, wind sea and swell sea. This is done by performing a linear ... -
Dynamic Amplification of Drag Dominated Structures in Irregular Seas
Horn, Jan-Tore Haugan; Amdahl, Jørgen; Haver, Sverre Kristian (OCEANS'15 MTS/IEEE;, Chapter, 2015)Offshore bottom-fixed structures, such as jackets, are typically designed with a natural period of 3 seconds or less. This means that there is limited dynamic excitation from wave loads at design sea-states. The benefit ... -
Estimation of Extreme Response - in a Jack-up Platform by Application of Stochastic Methods
Aarsnes, Lars Holterud (Master thesis, 2015)Abstract This thesis investigates different stochastic methods for estimating the extreme response on a jack-up platform in the North Sea. The extreme response of jack-ups is often heavily affected by dynamics and thus ... -
Investigation of Wave-Induced ULS and ALS Characteristic Loads and Responses on a Pile Structure in the Ekofisk Area - Importance of Breaking Waves
Overn, Ida Haftun; Waage, Ida Fredsvik (Master thesis, 2016)A set of metocean contour lines corresponding to annual exceedance probabilities of 10^(-2) and 10^(-4) describing the environmental conditions at the Ekofisk area are established based on hindcast data. These are divided ... -
investigation of which sea states yield the dominating contribution to fatigue accumulation in offshore structure
Mohammad Tahery, Hamed (Master thesis, 2015)In assessment of the fatigue damage, it has been assumed that the moderate sea states (significant wave height ranged between 4-8m) should have major influence on the offshore structures because they have relatively more ... -
Long Term Analysis of Semi Submersible Offset
Sandbakken, Sindre Schafroth (Master thesis, 2016)The objective of this master's thesis is to perform a long term analysis of a non-linear response problem using the Peak Over Threshold (POT) method. Offset of a semi submersible was selected as suitable response problem ... -
Modelling of Metocean Conditions for the Purpose of Planning Marine Operations
Laverton, Edward (Master thesis, 2015)The sea conditions of two areas, Haltenbanken and the Barents Sea, have been established in this project. Furthermore, a few cases of marine operations have been evaluated, among other topics. The fist part establishes ... -
Prediction of short-term wind and wave conditions for marine operations using a multi-step-ahead decomposition-ANFIS model and quantification of its uncertainty
Wu, Mengning; Stefanakos, Christos; Gao, Zhen; Haver, Sverre Kristian (Journal article; Peer reviewed, 2019)Short-term predictions of wind and wave properties with a duration of 1–3 days are vital for decision-making during the execution of marine operations. One-step-ahead weather conditions can be accurately predicted via ... -
Uncertainties in current measurements in the northern North Sea
Bruserud, Kjersti; Haver, Sverre Kristian (Journal article; Peer reviewed, 2017)A met–ocean measurement program of waves and current profiles at five locations in the northern North Sea was performed over a period of approximately 5 years. Despite quality control, the measured current speed data ... -
Uncertainties In Predicted Extreme Wave Induced Platform Response
Yao, Tianzuo (Master thesis, 2014)Before the long term response prediction is performed, a generic response function is firstly introduced. The generic response function is given as a function of weather characteristics in terms of hs and tp, and the shape ...