Hot spot stress parametric equations for three-planar tubular Y-joints subject to in-plane bending moment

Abstract Tripod substructure is widely used in the construction of fixed offshore wind turbines (OWT). The three-planar tubular Y-joint is a significant part of this type of OWT when conducting fatigue failure checking. In-plane bending moment is one of the typical loads applied to this structure. As no relevant research aimed to study the performance of three-planar tubular Y-joints subject to in-plane bending moment before, the works done in this paper are as follows: the calculation method for hot spot stress (HSS) of multi-planar joint was discussed; an experiment was carried out to reveal the strain distribution and verify the finite element (FE) method; a data set was built up with 1920 cases by validated FE model; the analyses of geometric parameters were conducted to derive a set of design equations; the parametric equations were evaluated via a common acceptance criteria.