Geometrical effects on the local joint flexibility of three-planar tubular Y-joints in substructures of offshore wind turbines

ABSTRACT

Although three-planar tubular Y-joints are amongst the most common joint types in jacket- and tripod-type substructures of offshore wind turbines (OWTs), local joint flexibility (LJF) of this type of connection has not been studied so far, mainly due to the complexity of the problem and high cost involved. Results of a parametric study conducted on the LJF of three-planar tubular Y-joints are presented and discussed in this paper. A set of finite element (FE) analyses were carried out on 81 FE models subjected to six types of axial, in-plane bending (IPB) moment, and out-of-plane bending (OPB) moment loadings in order to study the effects of geometrical characteristics of the three-planar Y-joint on the LJF factor (f_LJF). FE results were then used to develop a new parametric equation for the prediction of the f_LJF in axially loaded three-planar Y-joints, and the derived equation was checked against the UK DoE acceptance criteria.

KEYWORDS:

• Local joint flexibility
• LJF factor
• three-planar tubular Y-joint
• jacket and tripod substructure
• offshore wind turbine (OWT)

Acknowledgements

Useful comments of anonymous reviewers on draft version of this paper are highly appreciated.

Disclosure statement

No potential conflict of interest was reported by the author(s).