Next Article in Journal
Effect of Pressure on the Removal of NH3 from Hydrolyzed and Pre-Fermented Slaughterhouse Waste for Better Biomethanization
Next Article in Special Issue
Maintenance Optimization of Offshore Wind Turbines Based on an Opportunistic Maintenance Strategy
Previous Article in Journal
A Class of Energy Efficient Self-Contained Electro-Hydraulic Drives with Self-Locking Capability
Previous Article in Special Issue
Guidelines and Cost-Benefit Analysis of the Structural Health Monitoring Implementation in Offshore Wind Turbine Support Structures
Open AccessArticle

Response-Based Assessment of Operational Limits for Mating Blades on Monopile-Type Offshore Wind Turbines

Department of Marine Technology, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway
Centre for Research-based Innovation of Marine Operations (SFI MOVE), NTNU, NO-7491 Trondheim, Norway
Department of Engineering Sciences, University of Adger, NO-4879 Grimstad, Norway
Department of Mechanical and Industrial Engineering, NTNU, Richard Birkelands vei 2B, NO-7034 Trondheim, Norway
Author to whom correspondence should be addressed.
Energies 2019, 12(10), 1867;
Received: 3 April 2019 / Revised: 7 May 2019 / Accepted: 13 May 2019 / Published: 16 May 2019
Installation of wind-turbine blades on monopile-type offshore wind turbines is a demanding task. Typically, a jack-up crane vessel is used, and blades are individually lifted from the vessel deck and docked with the preinstalled hub. During the process of mating, large relative motions are developed between the hub and root due to combined effects of wind-generated blade-root responses and wave-generated monopile vibrations. This can cause impact loads at the blade root and induce severe damages at the blade-root connection. Such events are highly likely to cause the failure of the mating task, while affecting the subsequent activities, and thus require competent planning. The purpose of this paper is to present a probabilistic response-based methodology for estimating the allowable sea states for planning a wind-turbine blade-mating task, considering impact risks with the hub as the hazardous event. A case study is presented where the installation system consisting of blade-lift and monopile system are modelled using multibody formulations. Time-domain analyses are carried out for various sea states, and impact velocities between root and hub are analyzed. Finally, an extreme value analysis using the Gumbel fitting of response parameters is performed and limiting sea state curves are obtained by comparing characteristic extreme responses with allowable values. It is found that the limiting sea states for blade-root mating tasks are low for aligned wind–wave conditions, and further increase with increased wind–wave misalignment. The results of the study also show that the parameter T p is essential for estimating limiting sea states given that this parameter significantly influences monopile vibrations during the blade-root mating task. Overall, the findings of the study can be used for a safer and more cost-effective mating of wind-turbine blades. View Full-Text
Keywords: offshore wind-turbine; marine operations; blade root; probabilistic methods; planning offshore wind-turbine; marine operations; blade root; probabilistic methods; planning
Show Figures

Figure 1

MDPI and ACS Style

Verma, A.S.; Jiang, Z.; Ren, Z.; Gao, Z.; Vedvik, N.P. Response-Based Assessment of Operational Limits for Mating Blades on Monopile-Type Offshore Wind Turbines. Energies 2019, 12, 1867.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

Search more from Scilit
Back to TopTop