Structural performance of CHS X-joints fabricated from high-strength steel

In Memoriam of Prof. Dr. Bernt Johansson
Representative steel design standards have limited the use of high-strength steels to tubular joints, partly because of concerns about their unique material characteristics. However, the mechanical background behind the limitations is unclear, and its validity needs to be re-evaluated. In this study, a set of CHS (circular hollow section) X-joints fabricated from cold-formed tubes was tested under static axial compression. Then, as supplemental work, extensive test-validated numerical analyses were carried out to investigate further the behaviour of high-strength steel CHS X-joints. In both the testing and the analyses, where three steel grades covering ordinary to very high-strength steels were considered, the high-strength steel joints showed satisfactory structural performance comparable with that of ordinary steel joints in terms of strength and ductility.