Structural Damage Alarming Indices for Long-Span Bridges Based on Wavelet Packet Energy Spectrum

Two structural damage alarming indices including energy ratio deviation(ERD) and energy ratio variance(ERV) were put forward based on wavelet packet energy spectrum decomposed from the structural dynamic responses.For the Runyang Yangtze Cable-Stayed Bridge,the alarming capacity of two damage alarming indices was discussed with respect to damage location,damage extent and measurement noise.The simulation results compared with modal parameters,such as natural frequency reveal that damage alarming indices ERD and ERV can improve the sensitivity and effectiveness of damage alarming for long-span bridges together with preferable noise robusticity,which can be used for structural damage alarming of long-span bridges.