Structural Damage Detection of Continuous Beam by NExT Based Wavelet Packet Energy

Abstract

For the purpose of effective damage localization, combined with natural excitation technique (NExT) and wavelet packet (WP) decomposition method, a new algorithm named NExT based wavelet packet energy (WPE) damage detection algorithm was proposed for continuous beam. Finite measuring points of bridge structure response are set firstly, and then classified as reference points and response points. Calculated with each corresponding two-point, the virtual impulse response signals are taken as input data of WP decomposition method. Finally, structural damage detection is carried out by using WPE as damage index. Through a three-span continuous beam finite element model, this algorithm was discussed with respect to the applicability and effectiveness of damage detection. The analysis results reveal that, with certain robustness to noise, the proposed algorithm has favorable effect on damage interval localization. Therefore, the algorithm put forward is practical to detect damage of continuous beam.