Analyses Of Static And Dynamic Performance And Optimum Structural Design Of Urban Steel Struss Bridge

The thesis is based on an urban multi-girder steel truss bridge.A space finite element model is establish to analyze the static and dynamic characteristics of the whole bridge.In view of the unreasonable of the number of truss girder in multi-girder steel truss bridge,a method of layered optimization is put forward.The thesis analyze and optimize the characteristics of local orthotropic steel bridge deck.First of all,the development of steel truss bridge around the world is reviewed.What'smore,the thesis points out several design problems of steel truss bridge and list some traditional optimization methods.A finite element software MIDAS/CIVIL is used to establish a full-bridge analysis model based on beam element and plate elements.It systematically analyzes the deformations,stresses of the structure,the strength and stability of truss member under dead load and live load.In order to solve the problem that the number of truss is excessive,the thesis adopts a layered method.Firstly,through simple calculation,the reasonable number of truss is determined when the design parameters of the truss are unchanged.And then,the section parameters of the truss rods is optimized.Finally,the spatial finite element model of the optimized scheme is established to check the strength and stability of each truss rod.A finite element software MIDAS/FEA is used to establish a full-bridge analysis model based on plate elements and beam elements in order to analyze the local detailed deformation and stress of orthotropic steel bridge deck.The vibration characteristics of the bridge is analyzed.The reaction spectrum analysis was used to analyze the deformation and stress of the main beam and bridge pier under earthquake action,furthermore,the final calculation results is analyzed and verified.