Fatigue of K-Joints – Review and Outlook

Until the nineties the fatigue behavior of joints made of cold-formed and hot rolled hollow sections has been widely investigated. The results of the research led to the CIDECT Design Guide 8 in the year 2000 and ISO 14347 in 2008, which also form the basis for other recommendations. Since the nineties barley research have been made to the fatigue behavior of K-joints made of hollow sections. Thick-walled sections with low slenderness and high strength steel grades are not covered by recent design recommendations sufficiently. Therefore, a new research project is initiated by the Center of Competence for Tubes and Hollow Sections (CCTH) together with the Research Center for Steel, Timber and Masonry of KIT in Karlsruhe and TNO Structural Dynamics lab in Delft. A review of former investigations is building the basis for a comparison with new data gained in this running research. Both together, fatigue tests and numerical investigations will contribute to enlarge the dimensional range, to include steel grades up to 700 MPa.