Research On Fatigue Life Of Steel Box Girder With Corrugated Webs

With the rapid development of China's modernization process,the demand for traffic engineering,including bridges,is also getting higher and higher.Though the high-speed railway has a rapid development in China,the long-span steel box girder increasingly become the focus of scholars.The beam with corrugated steel webs is a new structure in the modern bridge which bending the web into a corrugated shape.The structure has its own advantages,with a light weight,good shear resistance,high capacity features and it also has a convenient construction.In recent years,China has begun to use the structure,and achieved good returns.Compared with the beam with corrugated steel webs and the steel box girder,the fatigue life of the new structure has been under study in the paper.The steel box girder with corrugated webs has reasonable procertt,structural material has the opportunity to bring into fully play and the structure accord with the light-duty demand.Besides,the steel box girder with corrugated webs also has a better economic and social benefits.In the thesis,fatigue behavior of the new structure is analyzed,describing the three methods for evaluating the fatigue life of railway bridges.Then,the paper has compared and analyzed the research methods and progress of fatigue load spectrum of railway at home and abroad.Besides,the size of the beam's cross section and the corrugated steel webs are designed through the research on the scheme of the steel box girder with corrugated web.The internal forces of each cross section of the structre is calculated,then the paper analysed the the shear buckling strength and fatigue performance of the structure.With ANSYS Workbench,a large-scale finite element software,a simulation analysis is made about the steel box girder with corrugated webs.The software simulates the fatigue life of the steel box girder with corrugated webs under fatigue load.It also analysed the the deformation of the steel box girder with corrugated webs under fatigue loading.Besides,the paper remodeled different parameter of the steel box girder by changing the geometric parameters of corrugated steel webs,such as the length,the height,the thickness and the inclination angle of the corrugated steel webs.The affect factors on fatigue life of corrugated steel webs are required through analysing the fatigue life of corrugated steel webs with different parameters and the recommendations of how to select the geometry parameters of corrugated steel webs are given.