Damage Detection Method For Beam Bridge Structure Based On Two Sensor Measurements

During the long-term service,the bridges suffer from vehicle loads,earthquakes,and collisions,which may lead to structural damage.If the damage(s)is/are not properly maintained or repaired in time,the damage will continue to accumulate,eventually leading to the collapse of bridges,which will cause great casualties and losses.Therefore,the research of structural health monitoring(SHM)is important for the operation of the bridge.To solve the current problems of excessive consumption of sensors high cost of SHM,this paper proposes a novel method using two sensor measured response locate the damage of the bridge under moving load.Main research are as the following four aspects:1.The background and significance of bridge health monitoring are introduced,The traditional damage identification methods and their merits and drawbacks are summarized.The research status of SHM in the world are systematically elaborated.Besides,the current challenges and difficulties of bridge monitoring are summarized and analyzed.Therefore the idea that using a small amount of sensors to do the damage detection is proposed in order to solve the problem of excessive sensor consumption.2.The theory of vehicle-bridge coupled vibration with moving loads and masses is introduced.The windowed cross-correlation function and the method of damage location with transfer entropy are presented.Taking the base frequency of the corresponding signal as a reference,a window of a certain length is defined.The windowed damage indexed are extracted using cross-correlation function and transfer entropy as the window moving along with the time series until the end.The damage indexed is utilized to locate the damage.3.Numerical Simulation.Through the simulation of the simply supported beam under the excitation of moving load,the effectiveness of the method based on cross-correlation function and transfer entropy is verified.The results prove that both methods are effective in numerical simulation of damage identification of bridge structures.4.Experimental Study.The beam structure test model was used for signal acquisition,and the effectiveness of the response signal based on cross-correlation function and transfer entropy was verified.The results show that the two methods can locate the damage successfully.