Wind-induced vibration flow control method of long-span bridges based on vortex generator

Abstract

The invention discloses a wind-induced vibration flow control method of long-span bridges based on vortex generator; the method comprises following steps: 1. selecting different spread installation spacing I of a vortex generator according to local prevailing wind direction and wind velocity and in combination of bridge section size; 2. for a main beam, the vortex generators are symmetrically arranged at two sides of the main beam; for a stay cable, the vortex generator is installed at lateral wind surface of the stay cable (the local prevailing wind direction is used as the wind direction). The invention utilizes the instability of the span-wise vortex in the wake area of a bridge main beam or stay cable as a disturbance source to suppress the formation and development of the large-scale span-wise vortex of the wake and to realize the control of the wind-induced vibration of the main beam or stay cable. The vortex generator is arranged at certain intervals in the span-wise direction to improve the flow field characteristics of the main beam or stay cable, and can effectively suppress or weaken the occurrence of vortex-induced vibration. Compared with the traditional vortex-induced vibration control method, the method has the advantages of easy installation, better universality and greatly reduced the cost of materials.

Description

technical field [0001] The invention belongs to the technical field of civil engineering, and relates to a method for controlling flow around a bridge girder or stay cables, in particular to a bridge wind resistance control method based on a vortex generator. Background technique [0002] With the continuous increase of bridge span, the structural stiffness and damping continue to decrease, resulting in the increase of bridge sensitivity to wind. Typical wind-induced effects such as flutter, buffeting, and vortex-induced vibration have gradually become key factors that need to be considered in the design of long-span bridges. Among the various wind-induced effects on the main girder of long-span bridges, flutter is a wind-induced vibration with a very obvious vibration response. Once it occurs, it will cause the danger of collapse and damage to the main girder of the bridge. Vortex-induced vibration will cause fatigue damage to the bridge structure. . Therefore, suppressing...

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Problems solved by technology

Although a lot of researches on passive methods of aerodynamic control have been carried out, they are all control methods based on the analysis of the flow field of two-dimensional bridge girder or stay cable section. Control devices are usually installed in the span direction of the main girder, which undoubtedly greatly increases the cost

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