Bridge Damage Detection Based On Vehicle-Bridge Coupling

In recent years,with the increase of the traffic volume and load,more and more bridges are suffering from disease.Bridge destruction and collapse accidents often occur.These accidents seriously endanger the safety of vehicles and people.So we need to detect and identify the bridges' damages as soon as possible.And we need accurately grasp the health of the bridges in order to timely repair and reinforcement.This paper studied the vibration response of vehicles under vehicle-bridge coupling by simply supported beam bridge.And this paper also studied the damage detection and identification of simply supported beam bridge by vibration signal of moving vehicle.The main research contents and achievements are as follows:1.In view of the shortcomings of the traditional methods of bridge structure damage identification,this paper focused on the analysis of the bridge structure damage identification method based on vehicle-bridge coupling.The theoretical basis of bridge damage identification based on vehicle-bridge coupling vibration was analyzed,and the analytical process of vehicle-bridge coupling theory was emphatically analyzed.The common signal processing methods are briefly introduced.2.The vehicle was not only the excitation input source but also the signal output source.The influence of vehicle parameters and bridge parameters on vehicle vibration response is studied by numerical simulation,include vehicle weight,vehicle speed,suspension stiffness and damping,tire stiffness and damping,bridge rigidity and the roughness of the bridge.It is concluded that the roughness of the bridge,vehicle speed,bridge rigidity and vehicle weight have great influence on vehicle vibration.Reasonable driving speed and vehicle parameters can obtain relatively stable vehicle vibration response.These are good advantages to damage identification.3.Damage identification based on a certain point of the bridge or vibration signal of the vehicle under the action of vehicle-bridge coupling is analyzed bymoving force and 1/4 vehicle.By collecting the acceleration time-history signal of the vehicle or the bridge at a certain point under the moving load or 1/4 vehicle when the vehicles pass through the damaged and undamaged bridges.Then the acceleration signal before and after the damage is made difference.The signal difference is identified by wavelet transform.4.A new detection method is proposed for old bridges without health data.The law and characteristics of the displacement response of the load contact point when the load moves on the damaged bridge with equal distance are derived theoretically.The feasibility of bridge damage identification based on vibration response difference of front and rear axle of vehicle is explained.The damage identification of the bridge is realized by simulating the displacement response of the contact point and the vibration response of the vehicle under the action of equidistant moving force and equidistant moving vehicles.An infinite rigid bridge method is proposed to remove the influence of roughness on vehicle vibration response and damage identification.The feasibility and accuracy of the bridge damage method based on vibration signal of front and rear axle vehicles are verified by simulation.