Local joint flexibility of completely overlapped tubular joints under in-plane bending

This paper presents parametric equations to predict the local joint flexibility (LJF) of completely overlapped tubular joints under lap brace in-plane bending (IPB). Finite element (FE) package MARC is adopted to simulate the joint with 8-node thick shell elements. The FE method is calibrated and verified based on the existing experimental database of completely overlapped tubular joints and simple T/Y-joints, respectively. A comprehensive parametric study is subsequently conducted to investigate the effects of non-dimensional parameters on the local joint flexibility coefficient (fLJF). Significative recommendations are presented to reduce the LJF of the joint. A set of parametric equations are developed based on 5184 8-node thick shell FE models and have been assessed against the acceptance criteria of the Fatigue Guidance Review Panel. The comparison of fLJF between the proposed parametric equations and the existing T/Y-joint parametric equations shows that the use of the latter to predict the LJF of completely overlapped tubular joints may not necessarily be appropriate.