Structural Damage Identification Of Bridge Based On Data-driven Method

Bridge is a representative infrastructure in civil engineering,which supports the development of social economy and provides people with convenient transportation.The bridge plays an extremely important role and must ensure that the bridge maintains its structural safety and stability in various environments.Since the development of structural health monitoring(SHM),researchers have proposed many methods to detect bridge structural damage.However,few scholars have studied the moment of damage occurrence.The timely identification of the moment of structural damage can provide timely information for damage early warning,and strive for valuable time for the maintenance of subsequent structures.Therefore,it is particularly important to discover the moment of structural damage in time.Once the moment of damage is determined,the location of the damage can be determined in a timely by the damage identification methods.At present,many large-scale bridges at home and abroad have installed structural health monitoring systems.How to effectively deal with and analyze these mass data for bridge health monitoring has become the focus of research.In order to solve the above problems,this article has carried out the following researches:(1)Referring to the relevant literature on structural damage identification at home and abroad,introduce the significance of bridge health monitoring and the research status at home and abroad,and several common methods for structural damage identification were briefly described,and their advantages and disadvantages were pointed out.In view of the problem of dealing with massive information,the idea of data-driven is more suitable for practical engineering detection.(2)On the basis of previous research,the moving principal component analysis method is proposed to detect the occurrence time of bridge damage.This method only analyzes the dynamic response of the structure,does not need the geometric behavior characteristics of the structure,avoids the difficulty of modeling,and can monitor the health status of the bridge in real time and continuously.Besides using the principal component as the damage indicator,this paper also puts forward the eigenvalue as the damage indicator,and the two indicators confirm each other,and the recognition effect is more accurate.(3)The finite element model of simply supported beam is simulated by ANSYS,and different degrees of damage are set up to verify the recognition ability of the method.In order to test the effect of application in practical engineering,the practical application results of the method are further illustrated through the analysis of experimental data and the data of active service bridge,and the different results of numerical simulation and practical application are discussed.(4)Structural damage identification by two step method,after determining the damage time,the wavelet packet transform is used to locate the damage,and the wavelet packet decomposition is carried out for the acceleration signals of each point before and after the damage to obtain the energy of each frequency band.The damage location indicator is calculated and the damage is located according to the maximum value of the damage indicator.