Blar i NTNU Open på forfatter "Ziegler, Lisa Sabine"
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Brief communication: Structural health monitoring for lifetime extension of offshore wind monopiles: can strain measurements at one level tell us everything?
Ziegler, Lisa Sabine; Smolka, Ursula; Cosack, Nicolai; Muskulus, Michael (Journal article; Peer reviewed, 2017)Operators need accurate knowledge on structural reserves to decide about lifetime extension of offshore wind turbines. Load monitoring enables us to directly compare design loads with real loading histories of the support ... -
Comparing a fracture mechanics model to the SN-curve approach for jacket-supported offshore wind turbines: challenges and opportunities for lifetime prediction
Ziegler, Lisa Sabine; Muskulus, Michael (Chapter, 2016)Accurate lifetime predictions are needed for support structures of offshore wind turbines to optimize operation and maintenance and to decide about lifetime extension of aging wind farms. A comparison of a facture mechanics ... -
Design optimization with genetic algorithms: How does steel mass increase if offshore wind monopiles are designed for a longer service life?
Ziegler, Lisa Sabine; Rhomberg, Matthieu; Muskulus, Michael (Journal article; Peer reviewed, 2018)Knowledge about the scaling of steel mass of monopiles is needed to decide for which service life an offshore wind farm should be planned. A computer-aided method to optimize monopiles for different fatigue lifetimes was ... -
Effect of Load Sequence and Weather Seasonality on Fatigue Crack Growth for Monopile-based Offshore Wind Turbines
Ziegler, Lisa Sabine; Schafhirt, Sebastian; Scheu, Matti Niclas; Muskulus, Michael (Journal article; Peer reviewed, 2016)Offshore wind turbines are subjected to variable amplitude loading, but the impact of load sequence is commonly neglected in fatigue analysis. This paper presents an initial investigation if load sequence and weather ... -
Fatigue crack detection for lifetime extension of monopile-based offshore wind turbines
Stutzmann, Jutta; Ziegler, Lisa Sabine; Muskulus, Michael (Journal article; Peer reviewed, 2017)Lifetime extension becomes increasingly crucial for industry, since the first offshore wind farms face the end of their design lifetime. The remaining useful lifetime of offshore foundations is driven by fatigue design and ... -
Fatigue reassessment for lifetime extension of offshore wind monopile substructures
Muskulus, Michael; Ziegler, Lisa Sabine (Journal article; Peer reviewed, 2016)Fatigue reassessment is required to decide about lifetime extension of aging offshore wind farms. This paper presents a methodology to identify important parameters to monitor during the operational phase of offshore wind ... -
Lifetime extension for large offshore wind farms: Is it enough to reassess fatigue for selected design positions?
Bouty, Corantin; Schafhirt, Sebastian; Ziegler, Lisa Sabine; Muskulus, Michael (Journal article; Peer reviewed, 2017)Fatigue reassessment within the decision process of lifetime extension might be uneconomical when individually performed for each turbine of a large offshore wind farm. This paper analyses the possibilities to extrapolate ... -
Probabilistic estimation of fatigue loads on monopile-based offshore wind turbines - Application to sensitivity assessment & clustering optimization for support structure cost reduction
Ziegler, Lisa Sabine (Master thesis, 2015)Offshore wind energy faces three important trends: (1) wind farms grow in size, (2) monopiles are installed in deeper water, and (3) cost reduction remains the most important challenge. With wind farm size, the importance ... -
Structural monitoring for lifetime extension of offshore wind monopiles: Verification of strain-based load extrapolation algorithm
Ziegler, Lisa Sabine; Cosack, Nicolai; Kolios, Athanasios; Muskulus, Michael (Journal article; Peer reviewed, 2019)Lifetime extension needs low-cost assessments that can identify the remaining useful life of offshore wind monopiles. A novel concept for load monitoring was developed that only needs strain gauges installed at one level ...