Blar i NTNU Open på forfatter "Sauder, Thomas Michel"
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Active truncation of slender marine structures: Influence of the control system on Fidelity
Sauder, Thomas Michel; Marelli, Stefano; Larsen, Kjell; Sørensen, Asgeir Johan (Journal article; Peer reviewed, 2018)Performing hydrodynamic model testing of ultra-deep water floating systems at a reasonable scale ischallenging, due to the limited space available in existing laboratories and to the large spatial extent ofthe slender ... -
Analysis of S–N data for new and corroded mooring chains at varying mean load levels using a hierarchical linear model
Lone, Erling Neerland; Maincon, Philippe Emmanuel; Gabrielsen, Øystein; Sauder, Thomas Michel; Larsen, Kjell; Leira, Bernt Johan (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 ... -
Controller Analysis in Real-Time Hybrid Model Testing of an Offshore Floating System
Vilsen, Stefan Arenfeldt; Sauder, Thomas Michel; Føre, Martin; Sørensen, Asgeir Johan (Chapter, 2018)This paper presents an experimental study using Real-Time Hybrid Model (ReaTHM) testing of a moored floating cylindrical buoy, conducted in a wave basin. ReaTHM testing is a method for studying the dynamics of marine ... -
Data-driven modeling of hydrodynamic loading using NARX and harmonic probing
Stamenov, David; Abbiati, Giuseppe; Sauder, Thomas Michel (Peer reviewed; Journal article, 2023)Optimizing floating wind turbines and their mooring systems requires validated computational models that predict wave-frequency and low-frequency hydrodynamic loads. Low-frequency loads are crucial for determining extreme ... -
Empirical estimation of low-frequency nonlinear hydrodynamic loads on moored structures
Sauder, Thomas Michel (Peer reviewed; Journal article, 2021)Low-frequency (LF) motions of floating structures are commonly modeled as the response of an oscillator to a second-order wave excitation. We present here an empirical method that reliably estimates the oscillators parameters ... -
Estimation of top tensions in mooring lines by sensor fusion
Sauder, Thomas Michel; Maincon, Philippe Emmanuel; Lone, Erling Neerland; Leira, Bernt Johan (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 ... -
Fatigue Assessment of Mooring Chain Considering the Effects Of Mean Load and Corrosion
Lone, Erling Neerland; Sauder, Thomas Michel; Larsen, Kjell; Leira, Bernt Johan (Peer reviewed; Journal article, 2021)Results from full scale fatigue tests of offshore mooring chains performed in recent years have revealed considerable influence of both mean load and corrosion condition on the fatigue capacity. It has been shown that a ... -
Fatigue reliability of mooring chains, including mean load and corrosion effects
Lone, Erling Neerland; Sauder, Thomas Michel; Larsen, Kjell; Leira, Bernt Johan (Peer reviewed; Journal article, 2022)A reliability formulation for mooring chain fatigue is developed, including the effects of mean load and degradation due to corrosion. They are included by starting from a S-N model with parameterized dependence to the ... -
Force Tracking Using Actuated Winches with Position-Controlled Motors for Use in Hydrodynamical Model Testing
Ueland, Einar Skiftestad; Sauder, Thomas Michel; Skjetne, Roger (Peer reviewed; Journal article, 2021)In this paper, we consider the problem of accurate force control using actuated winches, intended for use in real-time hybrid hydrodynamic model testing. The paper is also relevant to other cable-driven parallel robot ... -
Hydrodynamic testing of wind-assisted cargo ships using a cyber–physical method
Sauder, Thomas Michel; Alterskjær, Sverre Anders (Peer reviewed; Journal article, 2021)A novel empirical method to study wind-assisted cargo ships is presented. The physical ship model, including propulsion units, interacts in real-time with a numerical sail model during free-running tests. Loads from the ... -
Influence of Mean Tension on Mooring Line Fatigue Life
Lone, Erling Neerland; Leira, Bernt Johan; Sauder, Thomas Michel; Aksnes, Vegard Øgård; Gabrielsen, Øystein; Larsen, Kjell (Chapter, 2020)Studies published in recent years have documented a significant mean load effect on fatigue capacity for offshore mooring chain, and show that a reduction of the mean load gives an increase in fatigue life. However, current ... -
Kalman estimation of position and velocity for ReaTHM testing applications
Mehammer, Eirill Bachmann; Føre, Martin; Sauder, Thomas Michel; Chabaud, Valentin Bruno; Parisini, Thomas (Journal article; Peer reviewed, 2018)Offshore wind power research is a rapidly growing field, because of the present climate crisis and increasing focus on renewable energy. Model testing plays an important role in the risk and cost analysis associated with ... -
Method for Real-Time Hybrid Model Testing of ocean structures: Case study on horizontal mooring systems
Vilsen, Stefan Arenfeldt; Sauder, Thomas Michel; Sørensen, Asgeir Johan; Føre, Martin (Journal article; Peer reviewed, 2019)This paper presents a method for Real-Time Hybrid Model testing (ReaTHM testing) of ocean structures. ReaTHM testing is an extension to traditional hydrodynamic model-scale testing, where the system under study is partitioned ... -
Multiple-degree-of-freedom actuation of rotor loads in model testing of floating wind turbines using cable-driven parallel robots
Chabaud, Valentin Bruno; Eliassen, Lene; Thys, Maxime; Sauder, Thomas Michel (Journal article; Peer reviewed, 2018)Model testing of offshore structures in ocean basins has been accepted as a necessary step for the validation and calibration of numerical models, as well as for final design checks in extreme environments. While offshore ... -
OMAE2017-62498 Real-Time Hybrid Model Testing of a Top Tensioned Riser: a Numerical Case Study on Interface Time-Delays and Truncation Ratio
Sauder, Thomas Michel; Sørensen, Asgeir Johan; Larsen, Kjell (Chapter; Peer reviewed, 2017)This paper investigates the applicability of real-time hybrid model testing (ReaTHM testing) to the study of offshore systems in deep water. The focus is in particular on slender marine structures connecting floating ... -
Optimal Actuator Placement for Real-Time Hybrid Model Testing Using Cable-Driven Parallel Robots
Ueland, Einar Skiftestad; Sauder, Thomas Michel; Skjetne, Roger (Peer reviewed; Journal article, 2021)In real-time hybrid model testing, complex ocean structures are emulated by fusing numerical modelling with traditional hydrodynamic model testing. This is done by partitioning the ocean structure under consideration into ... -
Optimal Force Allocation for Overconstrained Cable-Driven Parallel Robots: Continuously Differentiable Solutions With Assessment of Computational Efficiency
Ueland, Einar Skiftestad; Sauder, Thomas Michel; Skjetne, Roger (Peer reviewed; Journal article, 2020)In this article, we present a novel method for force allocation for overconstrained cable-driven parallel robot setups that guarantees continuously differentiable cable forces and allows for small penalized errors in the ... -
Probabilistic fatigue model for design and life extension of mooring chains, including mean load and corrosion effects
Lone, Erling Neerland; Sauder, Thomas Michel; Larsen, Kjell; Leira, Bernt Johan (Peer reviewed; Journal article, 2022)A probabilistic model for mooring chain fatigue damage is developed based on the S–N approach. The effects of mean load and corrosion condition on the fatigue capacity of the chains are included by adopting a parameterized ... -
Probabilistic robust design of control systems for high-fidelity cyber–physical testing
Sauder, Thomas Michel; Marelli, Stefano; Sørensen, Asgeir Johan (Journal article; Peer reviewed, 2019)Cyber–physical empirical methods consist in partitioning a dynamical system under study into a set of physical and numerical substructures that interact in real-time through a control system. In this paper, we define and ... -
Real-time hybrid model testing of a braceless semi-submersible wind turbine. Part I: The hybrid approach
Sauder, Thomas Michel; Chabaud, Valentin Bruno; Thys, Maxime; Bachynski, Erin Elizabeth; Sæther, Lars Ove (Chapter; Peer reviewed, 2016)This article presents a method for performing Real-Time Hybrid Model testing (ReaTHM testing) of a floating wind turbine (FWT). The advantage of this method compared to the physical modelling of the wind in an ocean basin, ...