Baseline-free damage identification for small-medium span bridges using dual-sensor transfer entropy

Abstract This study proposes a baseline-free damage detection method for small-medium span bridges using dual-sensor transfer entropy under moving loads. In this method, acceleration responses are processed using frequency-adaptive moving windows, with the window length determined by the bridge’s fundamental frequency and the sampling rate. The windowed signals undergo L1-norm compression, generating damage factors through transfer entropy quantification. Damage localization is achieved by identifying peaks in the damage factor curve when the moving load traverses damage locations. Validation via numerical simulations and experimental testing confirms robustness and sensitivity for single and distributed damages across varying speeds, masses, damage quantities, and sensor layouts. The paradigm establishes a novel dynamics-informed monitoring framework achieving three key advances: (i) baseline-free diagnosis eliminating historical data dependencies, (ii) full-capacity damage localization with only two sensors, (iii) enhanced sensitivity to minute damage through vehicle-entropy synergy, enabling precise bridge assessment and overcoming key limitations in traditional vibration-based SHM.