Cable Force Monitoring And Evaluation Of Bridge State In Cable-stayed Bridge

As an important component of cable-stayed bridge,cable plays an vital function in the system of cable-stayed bridge.It can be seen that to command the Accurate cable force has a positive meaning in the process of cable-stayed bridge.At present,the cable force test method is more.The vibration frequency method is widely used for its simple and convenient,but also has its limitations.This paper will further explore the cable force test method,and research the impact of the cable-stayed bridge performance status when the cable force loss.Specifically,the main contents of this paper are as follows.The vibration frequency method is a simple,economical and convenient method that is widely used in the current cable test.In this paper,two theoretical methods of pre-stressing chord and clamped beam are described,which are simulate hinge support and clamped support to get the relationship between frequency and cable force.The results of the theoretical calculation formula and finite element calculation results by ANSYS finite element software are compared to prove that the two theories have higher accuracy.However,the vibration frequency method has its limitation,which can only measure the average cable force in a certain period of time,but can not get the time-varying cable force which the fatigue effect research is need.On this basis,the paper will come up with a method which based on wavelet analysis and extended Kalman filter to identify the time-varying cable force.Then,to prove that the wavelet-extended Kalman filter is very accurate by comparing the time-varying cable force obtained by numerical simulation with the time-varying cable force calculated by finite element method.Moreover,the paper will put forward the intelligent cable which based on fiber grating sensors for the time-varying cable force of the bridge which will be built.The intelligent cable is conducted by replace a wire or strand with a FRP which the fiber grating sensors have been embedded during the cable construction stage.And we can get the time-varying cable force by the change in the wavelength of the fiber grating sensor.Finally,to verify the accuracy of cable force test by intelligent cable.When we know the loss of cable tension based on the previous cable force test method,the influence of performance assessment on the cable-stayed bridge is analyzed.In this paper,the influence of important parameters such as cable tension,deflection and natural frequency of cable-stayed bridge is analyzed by ANSYS finite element software of Sutong Bridge.