Study On Dynamic Behaviour Of Cable Stayed Bridge And Health Monitoring

This paper taking the YuDao River Bridge as the research background, with an eye to the practical application. The work systematically analyses the nonlinear characteristics, static and dynamic analysis method of cable-stayed bridge. Especially for dynamic properties with much effort.The content of the paper mainly includes the following aspects:(1)Based on the ANSYS program, create Bridge structure finite element model, and for static and modal analysis.(2)Based on the MATLAB programs, compile a program which can get road roughness curve by road power spectral density function. Then based on APDL function of ANSYS, the vehicle–bridge interaction programs was done. The program can consider vehicle dynamic, bridge camber, road roughness, cable-stayed bridge nonlinear factors. At last, using the programs analyze YuDao River Bridge vehicle–bridge vibration response.(3)The seismic response analysis is carried on by adopting spectrum analysis and dynamic time-history analysis methods respectively, the two results are basically the same. Also, the dynamic behavours of extradosed prestressed bridge is analyzed.(4)Sensor placement is an important part of YuDao River Bridge health monitor system. An improved effective independence is proposed to optimize accelerate sensor placement for YuDao River Bridge. The new method concentrates sensor positions in high energy content regions, remedies defect of traditional effective independence. By analyzing, provide an effective, ecomomical three dimensions sensor placement menthod for YuDao River Bridge.(5)Cable is an important component of the cable-stayed bridge. Vibration method is a common method to estimate cable tension. Based on electromagnetic induction effect, this work design a new sensor based on electromagnetic induction effect to measure cable tension force. By indoor test, compare the data with that of acceleration sensor is obtained, the natural frequencies can be accurately obtained by the new sensor.(6)The proposed method takes the tension force, flexural rigidity and length as unknown parameters, analyzes the sensitivity of parameters to natural frequencies. The algorithm based on sensitivity-updating is able to simultaneously identify the tension force, flexural rigidity and length. The new method is applicable to the short cables and that with high bending stiffness.(7)Based on the vehicle weight-in-mionitor(WIM) system of YuDao River Bridge, and with reference to relevant literature, the vehicle load spectrum using to fatigue analysis was list. Adopting existing steel strand cable fatigue-life curve, According to the cable stress spectrum under vehicle load, the cable fatigue reliability within design reference period was analyzed. The results show that, only under vehicle load, regardless cable corrosion, all the stay-cables meet fatigue reliability indexes requirements.