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Wed, 08 January, 2020

Student Name

Sharda Lochan

Research Title

Fatigue performance of bolted connections of offshore wind turbines

Keywords

Fatigue, OWT, M72 bolt, transition piece, preload

Sponsor

TWI

Affiliated University

Cranfield University

Supervisors

Prof John Wintle and Dr Carol Johnston (TWI Ltd.), Dr Ali Mehmanparast (Cranfield University)

Start Date

02/10/18

Project Outline

The aim of this project is to investigate fatigue performance of flanged bolted connections of offshore wind turbines (OWT).These connections are used in OWT to connect the monopile/gravity base foundation to the transition piece (TP) and the TP to the tower. Forces and moments generated by the effects of winds, waves and currents subject these connections to variable amplitude loads and stresses. Areas such as the flange face, welds and bolts are vulnerable to fatigue cracking and failure as a result of in-service conditions, bolt relaxation, incorrect installation and manufacturing tolerances.

Currently there is uncertainty about the life of the bolts in-service and limitations to the methods used to calculate the life.The work carried out during this EngD will assist in optimising the inspection and maintenance schedules and in providing guidance to increase the level of confidence in fatigue life of bolted connections in OWT.

Publications

A review of fatigue performance of bolted connections in offshore wind turbines

https://www.sciencedirect.com/science/article/pii/S2452321619302410?via%3Dihub