TY - THES A1 - Thöns, Sebastian T1 - Monitoring based condition assessment of offshore wind turbine support structures KW - Structural condition assessment KW - Monitoring KW - Offshore wind turbine KW - Measurement uncertainty KW - Cost benefit analysis KW - Structural integrity management PY - 2012 UR - http://e-collection.library.ethz.ch/eserv/eth:6828/eth-6828-01.pdf U6 - https://doi.org/10.3929/ethz-a-009753058 SN - 0257-6821 IS - 345 SP - 1 EP - 149 PB - vdf Hochschulverlag AG, Zürich CY - Basel AN - OPUS4-28280 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thöns, Sebastian A1 - McMillan, D. T1 - Condition monitoring benefit for offshore wind turbines T2 - PMAPS 2012 - 12th International conference on Probabilistic Methods Applied to Power Systems CY - Istanbul, Turkey DA - 2012-06-10 KW - Condition monitoring KW - Offshore wind KW - Operation KW - Risk KW - Life cycle KW - Cost KW - Cost benefit analysis KW - Offshore wind turbine KW - Operation management KW - Structural integrity management PY - 2012 SP - 37 EP - 42 AN - OPUS4-26117 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Long, Lijia A1 - Anh Mai, Q. A1 - Morato, P. G. A1 - Dalsgaard Sorensen, J. A1 - Thöns, Sebastian T1 - Information value-based optimization of structural and environmental monitoring for offshore wind turbines support structures N2 - The use of load and structural performance measurement information is vital for efficient structural integrity management and for the cost of energy production with Offshore Wind Turbines (OWTs). OWTs are dynamically sensitive structures subject to an interaction with a control unit exposed to repeated cyclic wind and wave loads causing deterioration and fatigue. This study focuses on the quantification of the value of structural and environmental information on the integrity management of OWT structures, with the focus on fatigue of welded joints. By utilizing decision analysis, structural reliability methods, measurement data, as well as the cost-benefit models, a Value of Information (VoI) analysis can be performed to quantify the most beneficial measurement strategy. The VoI assessment is demonstrated for the integrity management of a butt welded joint of a monopile support structure for a 3 MW OWT with a hub height of approximately 71m. The conditional value of three-year measured oceanographic information and one-year strain monitoring information is quantified posteriori in conjunction with an inspection and repair planning. This paper provides insights on how much benefits can be achieved through structural and environmental information, with practical relevance on reliability-based maintenance of OWT structures. KW - Structural health monitoring KW - Offshore wind turbine KW - Monopile support structure KW - Value of information KW - Weld fatigue KW - Decision tree KW - Dynamic Bayesian Network PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-514098 VL - 10 IS - 159 SP - 1036 EP - 1046 PB - Elsevier Ltd. AN - OPUS4-51409 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -