Experimental set-up of the Double Slip Joint

Experimental set-up of the Double Slip Joint

Visser, N.

Metrikine, A. (mentor)

Mechanical, Maritime and Materials Engineering

Offshore engineering and dredging

European Wind Energy Master

2015-10-19

The Double Slip Joint (DSJ) is a new design to connect the transition piece to the foundation pile of an offshore wind turbine. It potentially offers high dynamic strength and reliability at a lower cost thereby assisting the decrease in cost of wind energy. The design is based on a self-locking principle through vertical settlement of the joint. The objective is to investigate the settlement behaviour of the DSJ through an experimental set-up. Three experiments including multiple tests were conducted. Experimental results have been compared with results from a finite element model in Ansys. The self-locking behaviour of the DSJ under various loading configurations including irregular environmental loading is confirmed. The DSJ settles through downward slip motions in the direction of the loading. Settlement depth increases when horizontal/vertical loads exceed previous applied loads or when their direction is changed 180 degrees. As the TP vertically settles the joint becomes stronger and more slip resistant. Slip will reduce to zero for suficient settlement. The conducted experiments led to a better understanding of the settlement behaviour and provided a benchmark data for validation of finite element models of this process. First the reader is introduced into the subject, the project definition and the approach is presented. Next, an explanation of the experimental set-up is given. Afterwards it is described how the scale model was designed and fabricated. The loading strategy is explained for three experiments. Then, the measured parameters and the data acquisition system is presented. The methods used to process the data is discussed. The most interesting results are presented in combination with a discussion and interpretation. Conclusions are made and lastly recommendations for improvement of the set-up, further testing and general development of the DSJ are given.

connection design
transition piece
offshore wind
support structure

http://resolver.tudelft.nl/uuid:b89b8b90-15d0-428c-8fd1-23ed2ed042eb

2018-10-19

Student theses

master thesis

(c) 2015 Visser, N.