General SCF design equations for steel multiplanar tubular XX-joints

This paper concentrates on the parametric stress analysis of steel multiplanar tubular XX-joints using the finite element method (FEM). A database of stress concentration factors (SCFs) at fixed hot spot stress locations was built up by carrying out about 320 runs of finite element (FE) analysis on 64 XX-joint models covering a wide range of geometrical parameters. Five different load cases of basic brace and chord axial load, in-plane-bending (IPB) and out-of-plane-bending (OPB) moments were considered. Through the parametric study, a set of SCF design equations was established for general end loading. An assessment study was carried out against the original FEM SCF database and two databases built upon experimental investigations. The assessment results satisfied the latest parametric equation acceptance criteria. This confirmed the accuracy and reliability of the proposed SCF design equations. In addition, practical examples were given to illustrate the application of such equations.