Damage Identification Method for Vehicle–Bridge Coupling Bridges Based on Variational Mode Decomposition

A method for rapid damage identification in bridge structures under complex environmental conditions is proposed, based on variational mode decomposition (VMD) and vehicle–bridge coupled vibration response. The vibration response of the vehicle–bridge coupling system is analyzed, and the VMD method is used to decompose the vehicle-bridge contact point signal, extracting intrinsic mode functions (IMFs) related to damage. Damage is quickly identified by observing abrupt changes in the IMF component curves. The results show that, even under various complex factors such as road surface roughness, different damage levels, bridge damping ratios, vehicle speeds, and environmental noise, the method effectively identifies bridge damage locations. As the damage severity increases, the abruptness of the IMF component curves becomes more pronounced. Furthermore, numerical simulations demonstrate that the method exhibits strong robustness to environmental noise, maintaining high identification accuracy across different conditions. The method demonstrates excellent adaptability and robustness in both single and multiple damage scenarios, confirming its effectiveness and practicality for real-world engineering applications.