Experimental study and numerical simulation of eccentric RHS column-to-I beam external diaphragm bolted connections with side plates

Abstract Bolted connections have been widely applied in steel structures because of the simplicity and economy of their fabrication and assembly. However, the behavior of steel bolted connections is a complex structural problem which involves various factors such as contact interaction, large deformation and non-linear material properties. So, the investigation of this behavior is a challenging subject in structural analyses. Generally, experimental test can provide reliable results that can describe the behavior of steel bolted connections, however, experimental work involves high cost, and in some cases, is not feasible, since numerical methods offer more flexibility and the possibility to investigate a wider range of parameters the experiments can cover, the research on steel bolted connections is further extended using the finite element (FE) method. By providing the complete stress state of the structure during its whole loading history, FE modeling can help understanding of the failure mechanisms. In this paper, three eccentric rectangular hollow section (RHS) column-to-I beam external diaphragm bolted connection specimens were tested. The aim of the tests was to find possible solutions for avoiding premature occurence of brittle fracture in RHS column-to-I beam connections. Test results show that the proposed bolted connections does not fail by fracture as observed in the conventional connections and has a larger energy dissipation capacity than the conventional types. As a result, it can be concluded that the proposed bolted connections are more suitable for applications in moment resistence frame in seismic regions.