System reliability of floating offshore wind farms with multiline anchors. (15th July 2018)

• Record Type: Journal Article
• Authors: Hallowell, Spencer T.; Arwade, Sanjay R.; Fontana, Casey M.; DeGroot, Don J.; Aubeny, Charles P.; Diaz, Brian D.; Myers, Andrew T.; Landon, Melissa E.
• Is Part Of: Ocean engineering. Volume 160(2018)
• Page Start: 94
• Page End: 104
• Publication Date: 2018-07-15
• Subjects: Floating offshore wind -- Multiline anchor -- Reliability -- Progressive failure; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2018.04.046
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: This research assesses the reliability of floating offshore windfarms utilizing two different anchor configurations: a conventional single-line system in which each anchor is loaded by a single mooring line and a multiline system in which each anchor is loaded by three mooring lines. While there are advantages to adopting a multiline system for floating offshore wind farms, the interconnectedness of this concept introduces disadvantages, such as reduction of system reliability and the potential for cascading failures among multiple structures. The reduction in system reliability is investigated here by running Monte-Carlo simulations in which mooring line and anchor demands and capacities are sampled from probability distributions. Demand distributions are generated through dynamic simulations with environmental conditions corresponding to the 500-year storm. Failure of mooring lines or anchors are initiated when their capacity is exceeded by their demand. The results of this research show that the reliability of the multiline system degrades significantly when progressive failures are taken into consideration. This research also shows that design considerations, such as the sizing of mooring lines and anchors and designing for single-line or multiline loads, significantly influence the system reliability of a floating offshore wind farm. Highlights: Multiline anchor systems could provide cost savings to FOWT wind farms. Introduction of multiline system alters reliability of entire system. Monte-Carlo simulation is used to model system behavior. Progressive failure can cascade amongst multiple structures. The reliability of the multiline anchor system is decreased compared to a similarly designed single line system.