Study On Dynamic Contact And Slipping Behavior Of Main Cable Steel Wire Of Suspension Bridge

The long-span multi tower suspension bridge is widely used in the construction of river crossing and sea crossing bridges,and the main cable is its key bearing component.When the main cable bends around the main cable saddle(the dangerous position of the main cable of the suspension bridge),the tension difference between the main cables on both sides of the main cable saddle results in the dynamic contact and "layered sliding" between the main cable strands and the steel wire,and the dynamic contact and micro sliding between the cable strands and the saddle groove and the clapboard.When the tension difference of the main cable on both sides of the main cable saddle is enough to overcome the total friction between the main cable and the main saddle,the main cable and the main saddle are prone to slip,which leads to the structural instability and even collapse of the suspension bridge.Therefore,it is very important to study the dynamic contact and slip behavior of the main cable steel wire of suspension bridge.In this paper,by constructing the finite element model of the contact between cable strand and saddle,the parameters of contact and slip between cable strand and baffle,saddle can be obtained;steel wire dynamic contact and sliding test bench is developed,which can carry out dynamic contact and sliding experiments between steel wire and steel wire,clapboard and saddle material;the dynamic contact and slip characteristics(contact state,slip curve,slip amount,friction coefficient,etc.)and the influence of contact slip parameters(slip amplitude,contact position,cycle number,load and material,etc.)are revealed by real-time in-situ observation.The results show that the contact state of steel wire with steel wire,clapboard and saddle material in one cycle is: adhesion-complete sliding-adhesion-complete sliding;With the decrease of the distance to the contact interface,the increase of cycle times and the reverse of the running direction of the upper steel wire,the transverse slip and the longitudinal deformation of the lower steel wire,the diaphragm and the saddle gradually increase;With the increase of the slip amplitude,the transverse slip of the lower steel wire first decreases and then increases,and the longitudinal deformation increases;With the increase of load,the transverse slip and longitudinal deformation of the lower steel wire increase gradually.