Study Of Damage Identification Of Stay Cables Based On Deflection Monitoring

The cable is one of the main stress components of the cable-stayed bridge,and it is also the component that can easily be damaged.Environmental erosion,strong wind and the long-term effect of vehicles will lead to corrosion or fatigue damage of cable,and the accumulation of damage to a certain extent will affect the safety of the operation of the structure,or even lead to the collapse of the structure.Therefore,it is of practical significance to use the response information collected by the bridge health monitoring system to master the working state and damage of the cable to ensure the safe operation of the cable-stayed bridge.Taking cable-stayed bridge as the research object,this paper deduces the mechanical relationship between the deflection increment of the main girder and the damage degree of the cable under the single or combined action of the dead weight of the bridge,the initial tension of the cable and the temperature load.Therefore,the identification of single or multiple damaged cable locations and damage degree is realized,and the finite element model of Yuehu Bridge is established for verification.The main research contents are as follows:Firstly,study the bridge orders weight of root and root damage occurs,the stay cables of the main girder deflection increment and cable damage condition between the forward problem and inverse problem,realize the occurred damage location and damage degree of the cable of accurate identification,damage identification process are given,and the linear elastic model is used for identification authentication.Secondly,the mechanical relationship between the deflection increment of the main girder and the damage status of the cable under the joint action of the dead load of the bridge and the initial tension of the cable is studied,and the accurate identification of the position and damage degree of the damaged cable is realized.The damage identification process is given,and the linear elastic model is used for identification authentication.Thirdly,the mechanical relationship between the deflection increment of main girder and the damage status of cable under the joint action of bridge dead load,the initial tension of the cable and temperature is studied,and the accurate identification of the position and damage degree of damaged cable is realized.The damage identification process is given,and the linear elastic model is used for identification authentication.Fourthly,the finite element model of Wuhan Yuehu Bridge considering the influence of geometric nonlinearity is established to verify the accuracy and stability of the proposed method in the damage identification of stayed cables.