Using Low-Strength Steel as Sacrificial Element in Column-tree Rigid Connections

In this study to evaluate the effect of high-strength steel and energy-absorbing steel in moment frame structures, a numerical investigation was undertaken of column-tree moment connections with three type of steels as ST37, ST19 and ST52. Also, in order to improve steel moment connections, the possibility of replacing the proposed model has been analyzed by common popular models. The results show acceptable ductility and energy absorption capacity and also stable hysteresis curves in the models which have been made of light steel in the plastic zone. As a result, using ST37 steel in plastic hinges of connections which were made of ST52 steel, increase the ductility(36%) and energy absorption(5.8%) in compared with column-tree connections which are fully made of ST37. Also applying ST19 in plastic hinges of ST37 connections will bring more ductility in a range of 64 percent and will increase the energy absorption. Accordingly, this study recommends this column-tree connection with combined steels as a good alternative for rigid connections