LAUSR

Abstract Steel structures are frequently preferred in the construction sector due to their lightweight and durability. Their durability, especially under static and dynamic loads, enables structures to effectively protect against external factors such as earthquakes. However, in addition to its advantages, various difficulties are encountered in joining steel structures with each other. In structures where bolts and welding connections are used intensely, weak points occur due to mechanical imperfections caused by secondary processes such as welding treatment, drilling hole etc. in the connection areas. Accordingly, the performances of different column-beam connections, which were welded by using HEB120 profile, under extreme loads were examined in this study. A total of nine samples were produced, all of them were tested with a large-scale three-point bending test device. As a result of the tests, force-displacement curves, energy absorption capacities and point displacement data with a stereo camera were collected. The fractographic examination was performed with SEM for the damage that occurred on the samples after the tests. In addition, nonlinear dynamic finite element analyzes were carried out in the explicit scheme in order to make further investigations, shorten the development process of new designs and simulate the fracture behaviour on samples after testing. The materials were modelled with elasto-plastic behaviour and for high strain values, the Swift-Voce hardening law was applied to extend stress-strain curves. The Hosford-Coulomb fracture model based on stress triaxiality, strain to fracture and lode angle parameter was used in order to reveal the onset of damage.