Strength equations of longitudinal plate-to-circular hollow section (CHS) joints

A parametric finite element analysis (FEA) has been carried out on X-joints of longitudinal plate-to-circular hollow section (CHS) loaded by in-plane bending in this study. The finite element models have been validated through comparisons with previous test results of X-joints. The models were utilized with different parameters such as; plate width-to-chord diameter ratio (AE '), chord diameter-to-thickness ratio (2 gamma), utilization ratio (U or n), and yield strength of the chord (F-y). The design strengths of joints suggested by current design equations (AIJ 2002, AISC 2005, AISC 2011, CIDECT 2008 and KBC 2009) were compared with the results of the FEA. Following this, a modified new design resistance equation, based on the FEA results, was proposed to more accurately estimate the capacity of X-joints.