Corrosion Simulation And Stress Redistribution Of Parallel Steel Cable Based On Cellular Automata

Cable system bridge,including suspension bridge and cable-stayed bridge,is one of the most common bridge types in China,and the cable is the most critical stress component.The cable is non redundant,and once the accident happens,the consequences are unimaginable.The corrosion of cable steel wire is one of the most common diseases of cable system,and the cost of bridge maintenance caused by corrosion is very high every year.Therefore,for the consideration of the long-term service safety of the bridge and the huge cost of the maintenance and management of the cable system bridge,it is very important to understand how the corrosion morphology of the bridge cable evolves and how it affects the mechanical performance of the cable.Based on the CA simulation algorithm and the cable steel wire corrosion mechanism,the electrochemical corrosion of metal and particle diffusion rules are simplified into specific CA rules.A cable corrosion model based on CA model is proposed.The evolution rules of cable corrosion morphology with time are explored,and the FA software is used for modeling of corroded steel wire,The influence of corrosion on the single wire and wire bundle model of the cable is obtained.Finally,based on the change of stress,a scheme of measuring point layout for monitoring the occurrence of corrosion is proposed.The main research contents and conclusions are as follows(1)The chemical mechanism of cable corrosion is summarized.The basic theory of CA algorithm and the method of simulating physical system are described.Considering the corrosion reaction driven by oxygen diffusion,the formation,deposition and hydrolysis acidification reaction of corrosion products,and the damage process of passivation layer on the surface of steel wire,a CA model of cable steel wire corrosion based on electrochemical reaction is proposed.(2)The evolution of corrosion morphology is simulated by using the CA model of cable steel wire corrosion,and the change rule of corrosion rate with time is obtained.The parameters of corrosion CA model were analyzed,and the effects of cell space size,corrosion cell concentration and passivation layer failure probability on CA model were explored.A method of coupling CA model with laboratory results is proposed.(3)The refined models of single steel wire and parallel steel wire bundle were established by using FA software,and the influence of corrosion morphology on the stress performance of cable was studied.The stress changes of cable steel wire under uniform corrosion and local corrosion conditions were obtained.Based on the stress changes,a measuring point layout scheme for monitoring cable corrosion was proposed.