SEISMIC BEHAVIOR OF STEEL FRAME CONNECTIONS WITH REPLACEABLE HIGH DUCTILITY AND ENERGY DISSIPATION COMPONENTS

In order to satisfy the urgent requirement of assembled steel structures with high ductility and energy dissipation capacity for the areas with high seismic intensity and population density, high performance low yield point steel is used for the connecting components of steel frame connections instead of ordinary steel. Then, the combination of prefabricated assembly function, ‘ductile energy dissipation fuse’ function and post-earthquake replaceable function is achieved with utilizing high-strength bolts. The non-linear finite element model of ABAQUS proves to be correct in simulating local buckling and bolt slipping phenomena based on published steel frame bolted connection tests at home and abroad. Based on this method, three types of bolted steel frame connections with connecting components using three different materials LYP100, LYP160 and Q235 were established. Their load-carrying capacity, hysteretic behaviour, cumulative plastic strain and energy dissipation capacity were compared, and the mechanism of connections with low yield point steel components was discussed. The results showed that using low yield point steel connecting components could change the failure mode of connections, make the plastic cumulative deformation mainly concentrate in connecting components, dissipate most of energy (around 90%), avoid the main frame encountering plasticity too early and effectively play a role of "ductile and energy dissipation fuse". The energy dissipation capacity of connections with low yield point steel components was higher than that of connections with ordinary steel components. When the rotation of connections reached 0.045 rad, the maximum elongation of low yield point steel components was much smaller than limit value, indicating that the components still had deformation capacity without premature fracture damage, which effectively improved the ductility of connections.