Suspension bridge refined dynamic analysis method based on double-beam model

Abstract

The invention discloses a dynamic modeling and dynamic characteristic solving method for a single-span suspension bridge. According to the method, a double-beam model connected by a plurality of discrete springs is adopted to perform dynamic modeling on the suspension bridge, the flexural rigidity of a main cable, the rigidity of a suspender and the action of axial force possibly borne by a main beam are considered, and meanwhile, the method is used for dynamic analysis of self-anchored and ground-anchored suspension bridges; a coupling vibration differential equation of the kinetic model is established, the method is solved by applying a dynamic stiffness method, and a suspension bridge frequency equation in a closed form is obtained; solving of the frequency equation is achieved througha numerical iterative algorithm, and then the modal frequency and the vibration mode of the system are obtained. The method is simple in process and clear in physical significance, is a frequency domain solution essentially, is good in stability and high in calculation efficiency, and has higher calculation precision compared with a traditional numerical solution, so that the method can be more reliably applied to dynamic analysis of an engineering structure.

Description

technical field [0001] The invention belongs to the field of structural dynamics, in particular to a refined dynamic analysis method for a suspension bridge based on a double-girder model. Background technique [0002] Suspension bridges are recognized as the main structural form of super-long-span bridges because of their simple structure, clear force, and strong spanning capacity. The analysis of dynamic characteristics of long-span suspension bridges is usually carried out by finite element method. Whether the structural stiffness, mass and boundary conditions can be correctly simulated will directly affect the accuracy of the analysis results, and the dynamic characteristics are the basis of structural wind and seismic analysis. Since the main cable of the suspension bridge cannot be replaced, and its safety is crucial to the load-bearing capacity and safety of the whole bridge, it is necessary to carry out detailed modeling analysis on its dynamic characteristics. Howe...

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Problems solved by technology

This kind of processing method will have the following problems when analyzing the dynamic characteristics of the main cable: (1) Since the bending stiffness of the main cable is ignored, when analyzing the side cable or the main cable with a small span, the calculation results are very poor. The error may be large; (2) It is difficult to take into account the additional cable force caused by the elastic elongation when the main cable vibrates

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