Browsing UiS Brage by Author "Pavlou, Dimitrios"
Now showing items 21-40 of 49
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FRP pipeline performance in tensional and torsional S-lay installation loads
Pavlou, Dimitrios (Peer reviewed; Journal article, 2021)The loading conditions of a composite pipeline is the main factor for its dimensioning. During S-lay offshore installation of multilayered FRP pipelines, severe tensional and torsional loads take place in the above sea ... -
Fuel Cell Powered Drone: Use of Fuel Cells to Extend Multirotor Drone Endurance
Apeland, Jørgen (PhD thesis UiS;, Doctoral thesis, 2021-10)Unmanned aerial systems can be used for a range of industrial applications to reduce risk, cost, and time. Fuel cell-based propulsion systems are outlined as a solution to extend mission endurance, one of the current main ... -
Gjennomgang av design, produksjon, vedlikehold, og reprasjonsmetoder av vindturbinblader
Åstveit, Håkon Heggernes (Bachelor thesis, 2022)Denne oppgaven er en gjennomgang om vindturbinblader. Med et design basert av aerodynamik- og gravitasjonkrefter, vil den inkommende vinden forårsake en rotasjon av bladene og starte produksjon av mekanisk energi. Moderne ... -
Implementation of linear, double-linear, and nonlinear fatigue damage accumulation rules for fatigue life prediction of offshore drilling top-drive tie-rods
Inoma, Jesse Ebubechu; Pavlou, Dimitrios; Zec, J. (Peer reviewed; Journal article, 2019-11)The offshore oil and gas industry has been exposed to major challenges over the last decade, particularly demanding cost cuts and more effective technical solutions. Predictive systems and remaining life assessments for ... -
Integration of a skid and hatch-based launch and recovery system for ROVs on USVs
Norstad, Vetle Chyba; Vaka, Herman Fossan-Waage (Master thesis, 2023)Subsea surveying plays a crucial role in the oil and gas industry by facilitating the maintenance, repair, and inspection of underwater equipment and infrastructure. As the demand for sustainable offshore oil and gas ... -
Integration of a skid and hatch-based launch and recovery system for ROVs on USVs
Norstad, Vetle Chyba; Vaka, Herman Fossan-Waage (Master thesis, 2023)Subsea surveying plays a crucial role in the oil and gas industry by facilitating the maintenance, repair, and inspection of underwater equipment and infrastructure. As the demand for sustainable offshore oil and gas ... -
Life Prediction for metals under multiaxial fatigue: A Review of existing multiaxial fatigue tests.
Tayem, Nour (Master thesis, 2022)An overview of multiaxial fatigue life prediction methodologies and tests is provided in the present paper. It is essential for engineering applications to accurately estimate the fatigue failure behaviour and fatigue life ... -
Mechanical design of latching/release mechanism
Laukvik, Lars Olav (Master thesis, 2022)This thesis documents the early development phase of a latch and release mechanism, where the goal was to make a 10mm separation within 10ms to break 4 electrical circuits. The thesis was proposed by Easee AS, a leading ... -
Mixed-mode I and II fatigue crack growth retardation due to overload: An experimental study
Rege, Kristen; Grønsund, Jørgen; Pavlou, Dimitrios (Peer reviewed; Journal article, 2019-12)Environmental loads acting on structures usually cause fatigue crack propagation under variable amplitude mixed-mode conditions. In order to better estimate the remaining fatigue life, the fatigue crack growth behaviour ... -
Modal analysis of offshore monopile wind turbine: An analytical solution
Pezeshki, Hadi; Pavlou, Dimitrios; Adeli, Hojjat; Siriwardane, Sudath C. (Peer reviewed; Journal article, 2022)An analytical solution of the dynamic response of offshore wind turbines under wave load with nonlinear Stokes’s wave theory and wave–structure and soil–foundation interactions is developed. Natural frequencies and the ... -
Nonlinear fatigue life prediction model based on the theory of the S-N fatigue damage envelope
Bjørheim, Fredrik; Pavlou, Dimitrios; Siriwardane, Sudath C. (Peer reviewed; Journal article, 2022)A nonlinear model is proposed in light of the theory of isodamage curves, to assess the cumulative fatigue damage under multistage loading. The isodamage curves were developed through the theory of the S-N fatigue damage ... -
Oppgradering av drivsystem til ein slangetrommel for gjødselslangar
Gjøstein, Olav Andreas (Bachelor thesis, 2022)Hovudmålet med denne oppgåva er å utvikla eit nytt design for kraftoverføringa til ein slangetrommel, produsert og seld av HMR Voss AS. Per i dag levera HMR gjødselspreiarar der slangetrommelen er ekstrautstyr. Gjødselspreiaren ... -
Optimization of Multirotor UAV Endurance
Sem, Sølve Sætre (Masteroppgave/UIS-TN-IMBM/2020;, Master thesis, 2020)Advancements in the technology of electric motors, batteries and control modules have facilitated a steep increase in the interest of small battery-powered multirotor aircraft. Unmanned areal vehicles (UAV) of this type ... -
Practical comparison of crack meshing in ANSYS mechanical APDL 19.2
Bjørheim, Fredrik (Masteroppgave/UIS-TN-IMBM/2019;, Master thesis, 2019-06)Structures under cyclic loading are typically subjected to formation of cracks, and thereafter crack propagation. To be able to analyse the crack propagation numerically with the goal of estimating a structure or a structural ... -
Preliminary design of a fuel cell - battery hybrid propulsion system for a small VTOL UAV
Brun, Ninni Sofie (Masteroppgave/UIS-TN-IMBM/2018;, Master thesis, 2018-06-14)Over the past decade, utilization of unmanned aerial vehicles (UAVs) in military and commercial applications has increased significantly. The vertical take-off and landing (VTOL) UAV is appreciated for its easy launch and ... -
A review of fatigue damage detection and measurement techniques
Bjørheim, Fredrik; Siriwardane, Sudath C.; Pavlou, Dimitrios (Peer reviewed; Journal article, 2021-09)A vast amount of research has been carried out towards the goal of quantifying changes related to the fatigue damaging process in materials throughout the fatigue life. However, no recommended practice has been developed ... -
Rocket Fuselage Development using Composite Filament Winding Technology
Kornberg, Stian; Aarlie, Caspar Johnsen; Samuelsson, Per Oskar (Bachelor thesis, 2024)This bachelor thesis is written in collaboration with the student organization UiS Aerospace, focusing on the production of the rocket fuselage for the Borealis program. The optimal production method was determined to be ... -
S-N curve for riveted details in corrosive environment and its application to a bridge
Adasooriya, Mudiyan Nirosha Damayanthi; Hemmingsen, Tor; Pavlou, Dimitrios (Peer reviewed; Journal article, 2020-01)A formula for stress‐life curve is proposed to predict the fatigue life of riveted bridges located in corrosive environments. The corrosive environment‐dependent parameters of the S‐N curve are determined based on the ... -
Sensitivity Study of Design Parameters for a Fuel Cell Powered Multirotor Drone
Apeland, Jørgen; Pavlou, Dimitrios; Hemmingsen, Tor Henning (Peer reviewed; Journal article, 2021)The use of multirotor drones for industrial applications is accelerating, and fuel cell based propulsion systems are highlighted as a promising approach to improve endurance – one of the current main limitations. Due to ... -
State of the art in structural health monitoring of offshore and marine structures
Pezeshki, Hadi; Adeli, Hojjat; Pavlou, Dimitrios; Siriwardane, Sudath C. (Peer reviewed; Journal article, 2023)This paper deals with state of the art in structural health monitoring (SHM) methods in offshore and marine structures. Most SHM methods have been developed for onshore infrastructures. Few studies are available to implement ...