Study On Carrying Capacity And Fatigue Of Rib-to-Deck Structure Of Locally Corroded In Orthotropic Steel Bridge Deck

The orthotropic bridge panels are widely used in large and medium span bridges due to their advantages such as light weight,large bearing capacity,large span capacity and beautiful appearance.However,with the increase of service time,service orthotropic steel deck will produce different degrees of rust in corrosive environment.There is little research on the influence of local corrosion on the performance of orthotropic bridge decks,which limits the use of orthotropic bridge decks to a certain extent.In view of the above problems,the tensile test of Q345C room temperature material under corrosive environment and the ultimate bearing capacity test and fatigue finite element analysis of the rib-to-deck structure of orthotropic steel deck under the partial corrosion of deck were carried out.The main contents of this paper are as follows:(1)The dimensions of the tensile test specimens of the raw materials of the rib-to-deck of the orthotropic bridge deck were designed,and the tensile test of electrochemical corrosion of Q345C steel at room temperature was carried out.Corrosion damages the Q345C material,the yield strength,ultimate strength,and elongation of the material decrease with the increase of the corrosion rate,but the effect of corrosion on the elastic modulus is not obvious.(2)The dimensions of the test specimens for the ultimate bearing capacity of the rib-to-deck of the orthotropic deck were designed,and the electrochemical local accelerated corrosion scheme and the static loading scheme of ultimate bearing capacity specimens were developed.The influence law of local deck corrosion rate on yield load,ultimate load,failure form,mid-span section and welds strain of near rib-to-deck was obtained,by the test of rib-to-deck ultimate bearing capacity of orthotropic steel deck with local corrosion of deck.(3)Established a finite element model consistent with the actual corrosion situation and size,and compared and analyzed the finite element simulation results with the test results.The results show that the simulation results are in good agreement with the test results,verifying the validity of the above finite element model.Partial rust redistribution of structural stress,the area of maximum stress began to decrease and shifted to the abrupt change of the cross section of the deck rust section.(4)Fatigue finite element models of rib-to-deck structure with different local corrosion parameters were established,and the fatigue stress of weld joint was analyzed based on hot spot stress method.It was obtained that the corrosion of the deck outside the rib had the greatest adverse effect on the fatigue stress of the welding toe of the deck.The fatigue stress of rib welding toe has the greatest adverse effect.