Flutter active blowing flow control device for steel box girder of long-span bridge

Abstract

A flutter active blowing flow control device for a long-span bridge steel box girder includes blowing branch pipes on both sides, blowing main pipes, a blowing power control device, and a wind speed and direction sensor. The blowing main pipe is arranged in the axis of a box girder structure at each side. The wind speed and direction sensor is arranged at the position where a box girder air nozzleaffects the incoming flow wind minimally. The blowing branch pipes on both sides are respectively connected with blowing ports. The multiple blowing ports are arranged at certain intervals in the direction of the span of the box girder on each side and the specific locations are as follows: the blowing ports are arranged on the upper edge of the box girder, the blowing ports are arranged on the upper edge of the air nozzle, the blowing ports are arranged at the lower edge of the box girder, and the blowing ports are arranged at the lower edge of the air nozzle. The wind speed and direction sensors are used for wind speed and direction measurement. The flutter active blowing flow control device in the invention is simple in structure, clear in control principle, and capable of well improving the flutter stability of the long-span bridge steel box girder.

Description

technical field [0001] The invention relates to a flutter active air blowing flow control device for steel box girders of large-span bridges. Background technique [0002] In 1940, the Tacoma Bridge with a main span length of 853.4 meters experienced serious fluttering phenomenon under the wind speed of 18m / s. The research on the control of bridge flutter has become an extremely important part of bridge wind engineering. Generally speaking, flutter is a kind of self-excited vibration with divergent nature of pure torsional or bending-torsional coupled vibration. When the airflow flows through the non-streamlined section, the phenomenon of flow separation and reattachment is easy to occur, and a relatively complex aerodynamic force distribution is formed on the surface of the structure. Due to the low stiffness of the main girder of long-span bridges, it is easy to generate vibration response under the action of aerodynamic force and in turn affect the surrounding flow fiel...

AI Technical Summary

Problems solved by technology

The traditional aerodynamic measures are all based on the two-dimensional flow field control method, which requires the installation of auxiliary devices in the span direction of the main girder. This method greatly increases the cost investment and has a certain impact on the original structure

Images