Static strength of thick-walled CHS X-joints subjected to brace moment loadings

Abstract

This paper presents results from a systematic finite-element (FE) study on the static strength of moment loaded thick-walled circular hollow section (CHS) X-joints, and compares the results with CIDECT and ISO/CD 13819-2 recommendations. For thick-walled joints subjected to brace out-of-plane bending, the CIDECT formulation excludes the γ dependency in the joint strength, which is different from the ISO equation and the present FE observations. The current study compares the different load paths mobilized in the X-joint under various brace loading conditions, through a detailed three-dimensional finite-element study. The numerical results reveal the significance of the joint geometric parameters and the tensile chord stress effect on the ultimate joint strength. Based on the present detailed study, a new chord stress function which incorporates the geometric dependency and the tensile chord stress effect is proposed. © 2007 ASCE.