Study On The Method Of Equivalent Quantitative Analysis For Corrosion Pits Of Steel Wire In Stay Cable

With the rapid development of transportation industry in China,cable-stayed bridges are widely used in infrastructure construction As the main load-bearing component in the system,the durability of stay cables directly affects the overall service life of the bridge,but the cable is easily corroded and corroded by corrosive medium.As one of the most common localized corrosion patterns,corrosion pits seriously affect the fatigue strength and residual life of steel wires.Based on the quantitative study of corrosion pits and the damage parameters of corrosion pits,analyzed the equivalent method of pitting corrosion and initial crack of steel wire.It has important engineering significance and practical value to further improve the prediction theory of remaining fatigue life of steel cable,improve the economic benefit of cable-stayed bridge,and ensure the safety of bridge operation.In this paper,the fitting degree of equivalent methods for corrosion pits of steel wire are studied.The main research work is as follows:(4)In this paper,five typical corrosion pits were selected,and the model of pitting corrosion pits corresponding to corrosion pits was established by using ABAQUS finite element software,comparing the model of stress and strain of size and distribution of stress intensity factor analysis,validity of pit the equivalent surface crack.Through the analysis of steel wire surface,pit bottom cross section stress,stress distribution,found to have similar effects of stress corrosion pits and cracks on the wire plane.(5)Taking the axial fatigue performance test data of old cable of the Xiangjiang Yinpenling cable-stayed bridge as sample,analyzed the fatigue fracture of each steel wire.On this basis,the ABAQUS finite element model of fine plane crack is established(6)According to the existing equivalent initial crack,damage parameter has been measured using fracture surface crack will be simplified to elliptical surface crack or circular surface crack.and the establishment of finite element model,calculated the stress intensity factor accordingly.Then the residual fatigue life is calculated by using the Paris formula,and the results are compared with the experimental data.Based on different damage parameters equivalent method has different fitting degree to the remaining fatigue life of corrosion pit.In practical engineering,the appropriate equivalent method should be selected according to the corrosion degree of steel wire.