A three-dimensional steel bridge tower vortex-induced vibration calculation method

Abstract

The invention discloses a three-dimensional steel bridge tower vortex-induced vibration calculation method, which achieves the three-dimensional steel bridge tower fluid-solid coupling numerical simulation through the dynamic mesh technology. The method comprises the steps of extracting the bending vibration mode coordinate values in the bridge direction and the transverse bridge direction througha Modal module of ANSYS workbench; performing function fitting by utilizing Matlab software to obtain a corresponding vibration mode function; inputting the vibration mode function into a user-defined program code UDF of the Fluent; analyzing the fluid to obtain a velocity field and a pressure field, obtaining generalized force by the user-defined program code UDF embedded into the Fluent, and substituting the generalized force into a structural vibration equation to solve to obtain generalized displacement; and obtaining an actual response of the structure through modal coordinate conversion, finally utilizing a dynamic mesh macro command to specify mesh movement so as to update the mesh position, and performing calculation of the next time step until convergence. According to the method, a computational fluid dynamics method is applied, and the business software Fluent is subjected to secondary development by compiling the user-defined program code UDF, so that the three-dimensionalsteel bridge tower fluid-solid coupling numerical simulation is achieved, the UDF can achieve parallel computing of the Fluent, and efficiency is greatly improved.

Description

technical field [0001] The invention relates to the vortex-induced vibration response of a steel bridge tower, in particular to a calculation method for a three-dimensional steel bridge tower vortex-induced vibration. Background technique [0002] The early cable-bearing bridges in my country were often ignored due to factors such as low pylon height, relatively simple cross-sectional form of pylons, and concrete pylon materials (with high structural damping ratio). Along with the continuous development of science and economy, bridge spans leap again and again, and the height of bridge towers also increases thereupon. From the perspective of convenient construction, concrete is no longer the only material used in bridge towers, and light-weight, low-damping-ratio steel materials are more and more widely used in bridge towers. Based on the above factors, the vortex-induced vibration of steel bridge towers in the construction stage of long-span cable-bearing bridges in the ne...

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Problems solved by technology

[0004] The wind tunnel test done by the above-mentioned scholars requires a lot of manpower and material resources, and the parameter adjustment is very inconvenient

Moreover, in the numerical simulation of fluid-solid coupling, they considered the two-dimensional model, and did not delve into the simulation of the three-dimensional variable cross-section model.

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