Influence Analysis Of Assembly Disparity Of Orthotropic Steel Bridge Structure And Countermeasures

In recent years,due to its special structure,orthotropic steel bridge decks have become increasingly popular in long-span bridges.However,the orthotropic steel deck structure inevitably shows dislocation deformation during the assembly process on the site,causing stress concentration at the deformation and increasing the fatigue of the steel deck.In this paper,the fatigue performance of orthotropic steel deck structures with assembly deviations is discussed and the fatigue life is studied.To avoid the excessive stress concentration due to assembly deviation,the corresponding countermeasures will be studied to reduce the local stress.This article not only has a very realistic engineering background,but also has important theoretical significance and practical value.The main work is as follows:1.Explained the research status of orthotropic steel deck structures,reviewed the fatigue theory of steel deck panels,summarized the fatigue design methods of steel deck panels,introduced existing fatigue life assessment methods,and summarized the concept of stress concentration factors and stress concentration on the impact of fatigue.2.Conduct stress analysis on the fatigue concerns of the orthotropic steel bridge deck structure to find the most unfavorable loading position for each point of concern.With the help of the ANSYS submodel technology,establish a physical model of the vertical seam of the top slab,which has three different kinds of errors.The table widths were respectively welded using 5 different slopes,and the stress variation law at the point of concern was studied.Based on the SN curve,the influence of the width and slope of the staggered table on the fatigue life of the roof was explored.The form of direct butt joints on the transverse joints of the top plate is used to analyze the effect on the fatigue life of the top plate.3.Based on the ANSYS submodel technology,a physical model of U-rib assembly deviation was established to investigate the effect of U-rib assembly deviation width on stress and fatigue life at the bottom and corner of U-ribs.The mesh size of the connection between U rib and bridge deck is discussed,and the optimal mesh size is determined.Under the optimal mesh size condition,the effect of U rib docking deviation width on the stress of interest is studied.4.Aiming at the assembly deviation problem of orthotropic steel bridge decks,the paper applies the two methods of pavement MPC and pasted CFRP materials to reinforce the roof assembly deviation,and studies the influence of the thickness of the reinforcement material on the stress of the concerned points;The problem was reinforced by two methods,U-rib internal filling material and reinforced top plate pavement.The influence of the material elastic modulus on the stress at the point of concern was investigated.