Effects of geometrical parameters on the local joint flexibility (LJF) of three-planar tubular T-joints in offshore structures

In this paper, the results of a parametric study conducted on the local joint flexibility (LJF) of three-planar tubular T-joints are presented and discussed. A set of finite element (FE) analyses were carried out on 81 FE models subjected to two types of axial loading in order to study the effects of geometrical characteristics of three-planar T-joint on the LJF factor (f(LJF)). Generated FE models were verified against available experimental data and parametric equations. The f(LJF) values in three-planar and uniplanar T-joints were compared. Results showed that the multi-planarity effect on the LJF is considerable and consequently the application of the equations already available for uniplanar T-joints to calculate the f(LJF) in three-planar T-joints may result in highly over- or under-predicting results. To tackle this problem, FE results were used to develop a new parametric formula for the prediction of the f(LJF) in axially loaded three-planar T-joints.

Automated summary

This paper presents the results of a parametric study on the local joint flexibility of three-planar tubular T-joints. The study found that the multi-planarity effect can significantly impact the results, which may lead to inaccurate predictions when using equations developed for uniplanar T-joints. A new parametric formula was developed based on finite element results for predicting the local joint flexibility in axially loaded three-planar T-joints.