Stress and strain concentration factors of completely overlapped tubular joints under lap brace IPB load

This paper presents parametric equations to predict the stress concentration factor (SCF) of completely overlapped tubular joints under lap brace in-plane bending (IPB) load. A completely overlapped tubular joint specimen is first tested for the verification and calibration of finite element (FE) models. The experimental results showed that the strain distribution near the weld toe is fairly linear. The maximum strain concentration factor (SNCF) of the joint occurs at the lap brace crown heel under IPB load. For the FE analysis, both 8-node thick shell and 20-node solid elements are suitable for modelling the joint. A set of parametric equations is proposed for predicting the SCF of completely overlapped tubular joints based on 5184 FE models. The parametric equations are verified against the acceptance criteria of Fatigue Guidance Review Panel. The assessment of the proposed equations is based on the database of FE analysis and test results. The comparison of SCF between the proposed parametric equations and the existing T/YT/Y-joint parametric equations showed that the results do not agree reasonably well under IPB load.