The Research On Stress Intensity Factor And Remaining Life Of Cable Wire With Multiple Corrosion Holes

Cable-supported Bridges have been widely used in the construction of transportation infrastructure in China due to the super-large spanning capacity,reasonable structural force and beautiful appearance.The cable is an important component in the cable-supported bridge.Affected by many factors,such as installation conditions,operating conditions and atmospheric environment,the cable wire often suffers corrosion damage in the early stage of service,which greatly reduces its safe operating life.In order to ensure the safe operation of cable components,it is necessary to thoroughly study the residual fatigue life of corroded steel wire deeply because the corrosion process of steel wire is unavoidable.The current research on the remaining fatigue life of the corroded steel wire usually adopts the simplified assumption of maximum single erosion pit.But in practice,there are often multiple typical pits adjacent to each other in the actual cable-corroded steel wire.The study on the influence of erosion pit group on the remaining fatigue life of corroded steel wire is not in-depth enough,and it is necessary to strengthen relevant systematic research work.In this paper,multi-corrosion pits are equivalent to multiple cracks,the stress intensity factor of the multi-corrosion pit group of cable steel wire is systematically studied,and the remaining life of the multi-crack steel wire is further tested and simulated,which can provide a reference for the prediction of the remaining life of the corroded steel wire.The main research contents are as follows:(1)Choosed the pit width and pit depth as equivalent parameters,the three-dimensional ellipsoidal pit and the long groove-shaped pit are equivalent to a two-dimensional plane semi-elliptical crack.The finite element software ABAQUS and FRANC3D were used for joint simulation.Studied the double The influence law of the tip stress intensity factor under different axial and circumferential distances of cracks,different axial distances of three cracks and four cracks and different crack sizes.(2)Based on the analysis of the stress intensity factor of the multi-crack steel wire,combined with the linear elastic fracture mechanics method,the propagation life of the corroded steel wire with the distribution of multiple crack groups is calculated,which provides basic theoretical data for the fatigue life test of the multi-crack steel wire.(3)The fatigue life test of the multi-crack steel wire was carried out,the texture of the fracture surface of the multi-crack steel wire and the remaining fatigue life distribution were analyzed,and the influence of the multi-crack on the remaining fatigue life of the corroded steel wire was studied.(4)Analyze the deviation between the test data and the simulation calculation data to verify the reliability of the simulation analysis;by analyzing the difference of the remaining fatigue life of the corroded steel wire under a variety of different corrosion pit group parameters,the applicable engineering conclusions are given.Provide a reference for the remaining life assessment of the cable corroded steel wire in the actual project.