Research On Anti-fatigue Design Of Orthotropic Steel Bridge Deck

Orthotropic steel deck is been widely used because of its light weight, low construction height, high ultimate bearing capacity, long service life, easy to manufacture and install, continuous structured and many other advantages. But it easily appears fatigue damage due to numerous panels, complex structure, welding residual stress and initial imperfection. Under this background, the fatigue properties of orthotropic steel deck are studied form two aspects of structural details and design parameters. The main work is as follows:(1) The research status of orthotropic steel deck was expounded. The basic theory of steel bridge fatigue was organized and reviewed.(2) According the engineering case, the parametric finite element models for global and local steel box girder were established. The stress characteristics of the orthotropic steel deck representative parts were analyzed. A certain equivalence between the simulation analysis method with finite element models and the laboratory model test was confirmed on the analysis of structure representative parts though comparing the results of simulation analysis with the laboratory model test data.(3) Based on the investigation and analysis of fatigue damage and combined with the relevant provisions of national standards, the fatigue properties of longitudinal weld between longitudinal rib and panel were analyzed with the two cases of crack originated in the weld toe and crack originated in the weld root, the fatigue properties of the arc opening shape for longitudinal ribs through transverse were analyzed with the two cases of transverse ribs appeared large surface deformation and transverse ribs appeared large vertical deflection deformation, and then the reasonable structure of these two kinds structure details were obtained.(4) The reasonable matching of the orthotropic steel deck design parameters was studied by introducing the orthogonal test method. The way to find the interactions through preliminary experiment was described. On the basis of the range analysis and variance analysis for finite element analysis results, the order and significant level of the effects impacted by design parameters were distinguished and the optimal combination of design parameters in test conditions was found.