Analysis Of Static And Dynamic Characteristics Of Little Grassy Suspension Bridge

Steel truss stiffening girder suspension bridges were very popular and built a lot in mountain or valley areas in recent years, because of its excellent spa nning capacity, beautiful modeling, as well as good economic performance. Un der the background of the steel truss stiffening girder suspension bridge under construction in Yunnan small gravel,this paper builds models and analyzes the spatial static and dynamic behavior of the bridge and then tests and makes a s imple analysis of its wind resistance perfor mance. The main research contents are as follows:1) Briefly describes the development of suspension bridges home and abr oad, characteristics of suspension bridge as well as the significance and the pr esent situation of structural mechanical characteristics o f suspension bridges res earches.. After that it introduces the calculation theories of suspension bridges,suspension bridge dynamic characteristics analysis and wind resistant analysis theories, and provides a theoretical basis for the following chapters of static an d dynamic characteristics analysis and wind loads test;2) Briefly introduces the situation of little grassy suspension bridge, gives finite element analysis and the initial equilibrium state of the bridge structure calculation and analysis. Based on these, the live load, temperature load and the combination of static analysis are given, then it attains the bridge and the ideal linear cable shape, the initial equilibrium state, the main cable the intern al force and displacement. The analysis is focu sed on the rules of live load, temperature effect of main cable and stiffening girder’s vertical displacement, theinternal force of main cable and hangers and changes. It finally carries on th e checking calculation to the role of the bridge under differen t loads combinati on, to ensure the normal operation of bridge safety;3) Analyze the self vibration characteristics of bridge operation state, the impact of temperature change, tower stiffness changes and other factors on th e dynamic characteristics of the bridge state, and gives the original design in t he cross set up the central buckle, concrete pouring the main truss chord of th e bridge dynamic characteristics simulation research; focuses on the stiffening g irder considering different torsional stiffness on the structural construction stage analysis of natural vibration characteristics, the bending frequency ratio effect on the bridge flutter stability is calculated, at the same time. According to the bridge of the stiffening beam connection scheme selection, this paper models and analyzes three kinds of connection methods of construction stage self vibration characteristics of the bridge effect;4) According to the specification and combined with the actual situation,determines the designed wind speed of the bridge, flutter and aerostatic stabili ty test speed, according to the finite element model and the experimental data of the bridge response it calculates the static windstability, flutter and buffetin g stability simple, and draws the corresponding results.