Large span bridge flow control wind resistance method based on breathing units

Abstract

The invention discloses a large span bridge flow control wind resistance method based on breathing units. The large span bridge flow control wind resistance method comprises the following steps that 1, breathing unit pipelines are mounted at sharp corners on the two sides close to the front edge and the rear edge of the bottom of a main beam, the breathing units are arranged in the breathing unitpipelines at equal intervals, inhaling air vents and exhaling air vents are correspondingly formed in the two ends of the breathing units, frequency conversion axial flow fans are arranged in the breathing units, and rectifying honeycomb devices are arranged in the air vents; 2, the frequency conversion axial flow fans are used for generating two different effects of inhaling and exhaling in the inhaling air vents and the exhaling air vents of the breathing unit pipelines, the breathing units serves as disturbance sources of a main beam flow around field, development of a wake flow large scalespanwise vortex is restrained, a downflow vortex is motivated, secondary wake flow instability is further motivated, and wind-induced vibration of the main beam is controlled. According to the largespan bridge flow control wind resistance method based on the breathing units, the breathing units serves as disturbance devices to improve the structure of the main beam flow around field, thus main beam wind-induced vibration is restrained, and the method has the advantages of efficiency, simpleness, wide application range and the like.

Description

technical field [0001] The invention belongs to the technical field of civil engineering, and relates to a wind resistance method for flow control of a long-span bridge. Background technique [0002] With the advancement of materials and improvement of construction methods, modern bridges are developing towards long spans, lightness, and flexibility. The structural stiffness and damping continue to decrease. The problem of wind-induced vibration of bridges is becoming more and more prominent. Wind effect has gradually become a key factor to be considered in the design of long-span bridges. In the wind-induced vibration of the main girder of long-span bridges, flutter is a kind of divergent vibration, that is, once it occurs, it will have the danger of collapse and damage to the main girder of the bridge; vortex-induced vibration is a limited vibration, which will cause fatigue damage to the bridge structure . Therefore, suppressing flutter and vortex-induced vibration of l...

AI Technical Summary

Problems solved by technology

Steady inhalation is an effective technical means to actively suppress the separation of the boundary layer around objects, which can effectively improve the flutter stability of bridges. The stability increases with the increase of inhalation energy, but excessive inhalation energy will make the flutter reduced vibration stability

The above methods all have the problems of low control efficiency, small control range and large limitations.

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