A fast analysis method for dynamic characteristics of three-span self-anchored suspension bridge

Abstract

The invention discloses a fast and refined analysis method for the dynamic characteristics of a three-span self-anchored suspension bridge. The method first provides a refined modeling method that can consider the flexural rigidity of the main cable, the elastic support of the main tower and the suspension rod. , on this basis, the differential equations of motion of the mid-span and side-span main cables and the stiffening beams were established respectively; the equations were solved according to the dynamic stiffness method, and the element dynamic stiffness matrix of the main cables and the stiffening beams was obtained. The overall dynamic stiffness matrix and frequency equation of the closed-form suspension bridge are obtained; then the frequency equation is solved accurately based on the numerical iterative algorithm, and the modal frequencies and mode shapes of the system are obtained. The process of the method is simple, and since all intermediate variables are given in closed form, it has higher computational accuracy and efficiency than existing solutions. The established self-anchored suspension bridge model is closer to the actual structure, the solution process is simple, the accuracy is high, and the efficiency is fast.

Description

technical field [0001] The invention belongs to the field of bridge engineering, and relates to a dynamic characteristic analysis method of a three-span self-anchored suspension bridge, which is especially suitable for rapid analysis of the natural frequency of the suspension bridge. Background technique [0002] In recent years, self-anchored suspension bridges have become more and more popular among urban bridges due to their graceful aesthetics and flexibility in site selection. Different from ground-anchored suspension bridges, self-anchored suspension bridges do not require large anchors, and their main cables are directly anchored at both ends of the main beam, thus greatly reducing the geological requirements of the bridge site, so it has gradually become a small and medium-span city. A competitive program for bridges. [0003] The analysis of dynamic characteristics of suspension bridges is the basis for seismic design, aerodynamic stability analysis, and coupled vi...

AI Technical Summary

Problems solved by technology

The former has a fast calculation speed and is mostly used in the preliminary design and rapid analysis of structures. However, due to the use of approximate displacement functions, the calculation accuracy is limited and it is difficult to use in the fine analysis of structures; the latter has strong applicability, although it can be used It is suitable for the overall and local analysis of complex structures, but its calculation accuracy and solution efficiency are a pair of contradictions, and it is difficult to apply to batch parameter analysis of large structures

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