Structural system identification based on combining weighted transmissibility and wavelet transform

Abstract

In this paper, an integrated method called WTs-OMA (weighted transmissibility and wavelet transform-based operational modal analysis) is proposed to identify the structural dynamic characteristics using the earthquake response of structures. The proposed method, which is a time–frequency domain method with both parametric and non-parametric characteristics, utilizes the effective and efficient capabilities of weighted transmissibility and wavelet transform to achieve a proper performance in modal parameter estimation. This method employs weighted transmissibility functions to identify natural frequencies and mode shapes and calculates the damping values using the skeletons or the single frequency signals obtained from wavelet transform of the correlation functions of seismic responses. In this research, a numerical model under El Centro earthquake excitation is used for performance validation of the proposed method; Furthermore, the Karun 3 arch dam is selected as a case study in which the dynamic characteristics of the structure are identified based on the seismic responses from the different earthquakes.