Development of Phenomenological Model for RC Circular Columns

The Modified Ibarra–Medina–Krawinkler (ModIMK) model, based on phenomenology, is widely used by earthquake engineering researchers due to its fast computation and effectiveness in simulating the performance deterioration of structural components. In the past, the main study objects were reinforced concrete (RC) square columns. However, RC circular columns have seldom been studied, and their ModIMK model still needs to be developed. For this reason, we collected the pseudo-static test data of 80 circular columns and calibrated the model parameters of each component; through the regression method, empirical equations between the design parameters and the hysteretic model parameters were established, i.e., the ModIMK model was determined. Using the hysteretic model in this work, the hysteretic responses of eight circular columns were predicted and found to be well fitted to the test hysteretic responses, verifying the model’s accuracy. This work enabled a more comprehensive and accurate application of the ModIMK model in earthquake engineering studies involving RC circular columns.