Browsing Institutt for marin teknikk by Journals "Marine Structures"
Now showing items 1-20 of 72
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A brute-force spectral approach for wave estimation using measured vessel motions
(Journal article; Peer reviewed, 2018)The article introduces a spectral procedure for sea state estimation based on measurements of motion responses of a ship in a short-crested seaway. The procedure relies fundamentally on the wave buoy analogy, but the wave ... -
A comparative analysis of the fluid-structure interaction method and the constant added mass method for ice-structure collisions
(Journal article, 2016)The constant added mass (CAM) method and the fluid-structure interaction (FSI) method are widely used to simulate ship-ship and ship-ice collisions. In the CAM method, the hydrodynamic effect of the surrounding water is ... -
A global slamming force model for offshore wind jacket structures
(Journal article; Peer reviewed, 2018)Under certain harsh environmental conditions, jacket structures supporting offshore wind turbines might be exposed to plunging breaking waves, causing slamming forces that affect the structural integrity and fatigue life. ... -
A semi-analytical frequency domain model for efficient design evaluation of spar floating wind turbines
(Journal article; Peer reviewed, 2019)A linear model for efficient design evaluation of spar floating wind turbines is presented, and verified against a nonlinear time domain model with regards to long-term fatigue and short-term extreme response for two ... -
Active heave compensation of floating wind turbine installation using a catamaran construction vessel
(Peer reviewed; Journal article, 2021)The application of floating wind turbines is limited by the high cost that increases with the water depth. Offshore installation and maintenance continue to consume a high percentage of the project budget. To improve the ... -
Algorithmic formulation of clay and sand pipe–soil interaction models for on-bottom stability analysis
(Peer reviewed; Journal article, 2021)This paper presents a new algorithmic formulation of the clay and sand pipe–soil interaction models recommended by the DNV-RP-F109 code for dynamic on-bottom stability analysis of submarine pipelines. The pipe–soil force ... -
An anisotropic friction model in non-bonded flexible risers
(Journal article; Peer reviewed, 2018)The present paper addresses small scale friction tests and an anisotropic friction model to predict friction for the interface between the anti-wear tape and tensile armors in non-bonded flexible risers. Small scale friction ... -
Analysis and design of offshore tubular members against ship impacts
(Journal article, 2018)Ship collisions may be critical to the operational safety of ships and offshore structures, and should be carefully designed against. This paper investigates the response of offshore tubular members subjected to vessel bow ... -
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 ... -
Analysis of S–N data for new and corroded mooring chains at varying mean load levels using a hierarchical linear model
(Peer reviewed; Journal article, 2023)Results from full scale fatigue tests of offshore mooring chains are analyzed. The data set includes new and used chains, tested at a variety of mean load levels. The used chains have been retrieved after operation offshore ... -
Critical assessment of hydrodynamic load models for a monopile structure in finite water depth
(Peer reviewed; Journal article, 2020)The response from steep and breaking waves for a monopile structure is investigated by analysis of experimental results and by application of numerical models for six irregular sea states. The experimental monopile was ... -
Design, Modelling and Analysis of a Large Floating Dock for Spar Floating Wind Turbine Installation
(Peer reviewed; Journal article, 2020)Installation of floating wind turbines at the offshore site is a challenging task. A significant part of the time efficiency and costs are related to the installation methods which are sensitive to weather conditions. This ... -
Design, structural modeling, control, and performance of 20 MW spar floating wind turbines
(Journal article; Peer reviewed, 2022)As floating wind turbines (FWTs) increase in size and power, the relative contribution of wave and wind loads to their global responses differs from what has been observed for 5–10 MW units. In addition, the larger deflections ... -
Development and verification of a time-domain approach for determining forces and moments in structural components of floaters with an application to floating wind turbines
(Journal article; Peer reviewed, 2017)Structural design of the floater is an important aspect in developing cost efficient and reliable floating wind turbines. It is difficult to well account for the effect of strong non-linear dynamic characteristics and ... -
Dynamic response analysis of a catamaran installation vessel during the positioning of a wind turbine assembly onto a spar foundation
(Journal article; Peer reviewed, 2018)Installation of floating wind turbines is a challenging task. The time and costs are closely related to the installation method chosen. This paper investigates the performance of an efficient installation concept – a ... -
Effect of long periods of corrosion on the fatigue lifetime of offshore mooring chain steel
(Peer reviewed; Journal article, 2022)R4-grade mooring chain steel specimens were subjected to alternating phases of saltwater corrosion and air fatigue to replicate seasonal load variations on chains in service. No significant difference in fatigue lifetimes ... -
Effects of a Passive Tuned Mass Damper on Blade Root Impacts During the Offshore Mating Process
(Peer reviewed; Journal article, 2020)Single-blade installation is a conventional method for installing blades on monopile-type offshore wind turbines. A jack-up crane vessel is commonly used, and individual blades are lifted to the tower top height and mated ... -
Environmental contours based on inverse SORM
(Journal article, 2018)It is well known that the full long-term response analysis is recognized as the most accurate and reliable method for evaluation of the extreme response in the design of ships and marine structures. However, such a method ... -
Environmental lumping for efficient fatigue assessment of large-diameter monopile wind turbines
(Peer reviewed; Journal article, 2021)Fatigue damage is one of the governing factors for the design of offshore wind turbines. However, the full fatigue assessment is a time-consuming task. During the design process, the site-specific environmental parameters ... -
Estimation of top tensions in mooring lines by sensor fusion
(Peer reviewed; Journal article, 2022)The paper describes a sensor fusion method that provides reliable, uninterrupted and bias-free estimates of the top tension in a mooring line. The method exploits the geometric nonlinearity of mooring systems installed in ...