2023

Alshawwa, Omar; Mela, Kristo; Ahola, Antti; Björk, Timo

High strength steel (HSS) hollow sections are widely available for structural applications nowadays. A typical structure employing HSS hollow sections is a truss with welded joints. The behavior and design of HSS welded tubular joints still includes some open issues, and so-called K-joints require more experiment-based research. This research addresses the effect of specific parameters (chord preloading and the gap size) on the behavior of welded HSS K-joints made from cold-formed hollow sections. These parameters have been selected based on their limited conducted research. In the experiments the degree of chord tension preloading and gap size were varied to obtain a broad scope for the study. This study of the aforementioned parameters was conducted on 6 welded HSS K-joints of grade S700. The study is entirely based on experiments targeting the effect of each parameter in a comparative manner. The tested joints were fabricated with full strength butt and fillet welds and were designed to target one type of failure in K-joints to occur which is chord face failure. Subsequently, the load-displacement behavior of the tested joints is reported. The experimental results are compared with the expected behavior according to the most recent version of the second generation Eurocode. The level of agreement between the tests and current guidelines is compared and analyzed. Accordingly, this research contributes to the ongoing discussion on behavior and resistance of welded HSS hollow section joints.