Damage Identification for Orthotropic Steel Bridge Girder Based on Wavelet Packet Permutation Entropy

In light of the susceptibility of steel box girder orthotropic plates to damage and cracking, the test data is utilized for structural damage identification. Vibration acceleration data is subjected to wavelet packet decomposition (WPD) and reconstruction, and permutation entropy (PE) is introduced to construct a damage index based on permutation entropy difference (PED). Through the non-destructive and damage dynamic test of the orthotropic steel bridge deck, the acceleration response signals of the components in the non-destructive and damaged states are respectively subjected to wavelet packet decomposition. Next, identify the component with the highest energy post-normalization for reconstruction. Subsequently, compute the permutation entropy of the reconstructed signal and ultimately perform damage identification by analyzing differences in permutation entropy. Additionally, a numerical simulation is conducted to establish the orthotropic steel bridge deck model, and the robustness of the wavelet packet permutation entropy to noise interference is analyzed. The research findings demonstrate that the wavelet packet permutation entropy-based structural damage identification method is highly sensitive to damages and robust to noise interference.