Structural damage estimation in mid‐rise reinforced concrete structure based on time–frequency analysis of seismic accelerograms

Abstract

The aim of this study is to evaluate the intensity and damage potential of seismic accelerograms on structures combining a fuzzy inference system with a set of new seismic intensity parameters. The proposed seismic parameters stem from the energy content of seismic signals. More specifically, a time-window is utilised to define the strong motion duration of seismic excitations and the ensemble empirical mode decomposition is employed for a time–frequency analysis of the selected strong motion area. The maximum inter-storey drift ratio is selected as the seismic structural damage index. Strong interdependence between the proposed seismic intensity parameters and the selected damage index is reported. The membership functions of the fuzzy system are tuned by means of a genetic algorithm. The effectiveness of the proposed fuzzy model is tested on a reinforced concrete frame structure. The methodology should be repeated for every new examined structure and it can be applied to other building types with minor changes. Numerical results indicate total mean square error <0.25 for the maximum inter-storey drift ratio estimation and 91% correct classification rate to seismic categories, revealing the effectiveness of the fuzzy model to estimate numerically the structural damage.