Seismic Damage Identification of Masonry Pagodas Based on Wavelet Packet Energy Variation

ABSTRACT A method for identifying structural damage in masonry pagodas based on wavelet packet energy variation was proposed, with the change in wavelet packet energy of dynamic response signals before and after structural damage being used as the damage indicator. Finite element software was employed to establish a numerical model of the Kaiyuan Pagoda. By introducing different types of damage and applying seismic waves in three directions under four working conditions, a seismic response analysis was conducted. The acceleration response signals at feature points on each floor of the structure were subjected to wavelet packet transformation, and the wavelet packet energy was calculated. Based on the wavelet packet energy variation (DSI), damage indicators were determined, and structural damage identification was carried out. The identification results were compared with the preset damage. The results showed that, in the absence of noise interference, the damage indicators clearly correlated with the damage of the masonry pagoda, enabling accurate localization of the damage. Even when Gaussian white noise was added to the acceleration dynamic response signals, the indicators could still accurately identify the damage location, demonstrating good noise resistance. The research results provided an effective method for the damage assessment of masonry pagodas.