Parametric Equations to Predict SCF of Axially Loaded Completely Overlapped Tubular Circular Hollow Section Joints

This paper presents a set of parametric equations for predicting the stress concentration factor (SCF) at the crown toe, saddle, and crown heel of completely overlapped tubular circular hollow section joints under lap brace axial compression. In the study, a joint specimen is tested within the elastic limit of steel material for the verification of finite-element (FE) models. The comparison of results showed that the 8-node thick shell and the 20-node solid FE models simulate reasonably well the test specimen with average difference in strain concentration factor (SNCF) of 7.9 and 8.8%, respectively. The mean SCF-to-SNCF ratio of the joint is 1.15. The parametric equations are developed based on 5,184 8-node thick shell FE models and have been assessed against the Fatigue Guidance Review Panel criteria, the current and previous test data and the FE database. The results of the statistical analysis, which based on the frequency of occurrence of predicted-to-measured SCF, showed that the performances of the proposed parametric equations are acceptable.