Hysteretic model and application of a metallic damper with two-phased energy dissipation

This paper presents an investigation into the hysteretic model and application of a shape-optimized composite metallic yielding damper (SCMYD) which enables two-phased energy dissipation. First, a trilinear hysteretic model considering the phased yielding characteristics of SCMYD was developed and the calculation of the parameters in the model was determined. Moreover, the predictions of the model were compared with the experiments. Results indicated that the proposed trilinear model is appropriate for describing the hysteresis characteristics of SCMYD with an average error in energy consumption of 8.22 %-17.78 %. Then, SCMYD was applied to a reinforced concrete column-steel beam hybrid frame (RCSHF) to enhance the seismic performance of the structure. The design requirements for the components in RCSHF with SCMYD were described. Furthermore, based on the proposed trilinear model, the seismic performance of traditional reinforced concrete column-steel beam frame (RCSF) and RCSHF were compared by numerical analysis. In addition, the phased energy dissipation of SCMYD in RCSHF was evaluated. Results suggested that the RCSHF designed according to the proposed principles is able to fulfill the desired yielding mechanism. It is superior to the RCSF in terms of loading capacity, initial stiffness and energy dissipation capacity. Compared to RCSF, RCSHF exhibits a significant decrease in the interstory drift ratio and roof displacement. Besides, SCMYD in RCSHF is capable of phased energy dissipation under frequent and moderate earthquakes as expected, and the energy consumption percentage of SCMYD is higher than 60 % under different earthquake levels.