移动车辆激励下梁桥位移影响面重构及损伤诊断方法OA北大核心CSTPCD

Aiming at the problems of the limitation of considering only one-dimensional loading effects on bridge influence lines,and the inability to account for lateral load effects on the structure,as well as the challenges posed by structural dynamic responses and the multi-axial effects of vehicles in extracting bridge time-history responses in vehicle excitations,a method for the reconstruction of bridge influence surfaces and damage diagnosis was proposed.This method was based on variational modal decomposition and L2 regularization.Firstly,the vehicles were simplified as line loads and the original time-history responses of each lane of the bridge were obtained by separately applying loading from single heavy vehicles on multiple lanes.The variational modal was utilized to separate dynamic components from the time-history responses.Subsequently,a mathematical model was established based on vehicle axle spacing and sampling frequency to identify the vehicle information matrix and recognize the influence lines,thereby eliminating multi-axial effects of vehicles.Secondly,L2 regularization was employed to identify the bridge influence lines.Through lateral interpolation,the influence lines for each lane were reconstructed into influence surfaces.Finally,a damage localization was achieved using an influence surface difference indicator.A finite element model of an actual three-span steel-concrete composite beam bridge was established.The structural dynamic model was refined using frequency relative error and modal confidence criteria.The feasibility of the proposed method was validated by the corrected model.The results show that the proposed method can accurately reconstruct real bridge influence surfaces,and the use of influence surfaces for structural damage localization is more intuitive and reliable.