Damage Detection of RC Moment Frame Structure Based on Multi-Objective Nonlinear Model Updating Under Earthquake Excitation

Abstract This paper aims to propose a method of evaluating seismic damage on reinforced concrete moment frame structures with nonlinear finite element (FE) model updating. The proposed model simulates the nonlinear behavior of structures with Modified Ibarra–Medina–Krawinkler (MIMK) model and searches the parameters of the MIMK model with FE model updating. To reflect nonlinear local seismic behavior into the model updating, local structural response as well as global structural response are considered in the objective functions. To minimize two objective functions that are discrepancies of local strain and global displacement response between model and acquired data, multi-objective optimization algorithm is employed. To select the optimal solution among multiple solutions derived from model updating, an equation including a weight factor is proposed. The response of the updated model, which corresponds to the optimal solution selected by the equation including a weight factor, is validated by comparing it with the measured response, and the damage is evaluated using the hinge propagation and drift ratio of the updated model. In addition, the effectiveness of the proposed model is validated by using the high-intensity earthquakes that have not been used in the model updating procedure through nonlinear seismic response prediction and damage state identification.