Critical analysis of MP-TP wedge connection concept for application in offshore wind turbines

The main technologies that have been employed in the offshore wind industry for connecting the monopile foundation to the transition piece (MP-TP) are the grouted connection and threaded connection. The latter has been widely used in the majority of offshore wind farms developed in the last decade. However, as the offshore wind turbines get larger in size to increase the level of produced electricity, there is an essential need to re-evaluate the use of threaded joints as the current main choice for MP-TP connections and develop new MP-TP concepts which offer lower costs. An innovative MP-TP technology which has been developed for application in offshore wind industry is the wedge connection concept. In this paper, an independent study has been conducted through analytical evaluation and finite element analysis to understand the technological benefits that this concept offers. The study has been developed in three different steps: design of hole geometry, stress distribution prediction and a real-case scenario to evaluate the strength of the system under different loading conditions. The results from this study have been discussed in terms of the main advantages that the wedge connection technology offers as an alternative MP-TP concept for offshore wind applications.