Performance of externally reinforced CHS X-joints subjected to axial loads

Abstract

Circular hollow sections (CHS) have evolved as the primary choice for the tubular lattice structures, due to their excellent mechanical properties and aesthetic appearance. However, enhancing the joints capacities in such structures poses as challenge to structural designer. Recent research addressed several external reinforcing schemes that can be utilized for strengthening CHS X-joints. Although each of these schemes was studied thoroughly, no collective study was conducted to compare between their efficiencies in enhancing CHS X-joints strengths and stiffnesses. This study focuses on evaluating the structural performance of these techniques relative to each other. The results showed that CHS X-joints strengthened using outer flanged pipe to confine brace-chord intersection achieved the highest strength and stiffness enhancement among the examined joints. Also, it proved that joints strengthened with single or double outer stiffeners yielded acceptable capacity enhancement with the advantages of easy fabrication and acceptable aesthetically appearance.