Research On Mechanical Property Of Joint Area For Large Span Steel-Concrete Truss Girder Composite Brifge

As a new structure used in the bridge, steel-concrete composite structure already has beening a long history of development. Because of its good mechanical performance and economy, this type of structures shows broad application in the actual project. The optimal combination of the two connections is the key to the design of these structures. For steel-concrete composite truss bridge, the study of mechanical properties of composite joints and the design that optimize them are essential. This type of structures still need to be explored and improved in China, and thus the research and analysis of truss girder bridge nodes will become typical subjects which have theoretical and engineering significance.In this thesis, the characteristics and development of composite truss bridge are briefly stated. Jin-Shan yellow river bridge is set as an example, so the node area of this composite truss bridge can be established a finite element model for mechanical analysis. Through the establishment of the constraint equations to simulation the interaction between steel and concrete simply and reasonably, taking into account the part of the material and geometric nonlinear effects to the structure to calculate and analyze the main deformation properties of the node, the stress state and bearing capacity under the design load and test load of500t. So the curve of load-displacement and stress-strain of node model can be gained. A model test with a ratio of1:2is stated in this thesis. And the preparation and implementation of the test are minutely illustrated to analyze experimental phenomena and results. The test results indicate that steel cracking near the weld of node webs and chords at the intersection is design need to focus on. Finally, the finite element analysis and test results are compared and they fit well.Finite element analysis can offer theoretical guidance and reference for the model test and the actual project.Through the above comparative analysis, it is known that this type of composite nodes have high stiffness, high capacity and definite force transfer. It can meet the design requirements of the actual project. Meanwhile, analyzing information and material used for comparative analysis are offered for the same type study of structure and accumulation. Finally, the need for further research and analysis are put forward in the thesis.