VIV Aerodynamic Interference Effects Analysis Of Suspension Hinged Style Sling

As is known to all,suspension bridge is a kind of bridges that takes the cable that under tension as an important bearing component,and it’s a typical of a flexible structure. However,suspension bridge and its components(such as main beam,main cable, sling, etc.) occurs vortex-induced resonance response easily under the conditions of constant wind due to the suspension bridge structure’s light weight and low damping. Therefore,the VIV research of suspension bridge with hinged style sling is very necessary and meaningful.In order to discuss that use numerical method to investigate the VIV phenomenon of suspension bridge,the paper takes a long-span suspension bridge with articulated sling as the background,using the fluid-structure coupling simulation that combines Computational Fluid Dynamics software CFX and ANSYS Structure modeling software Workbench to simulate the VIV of the suspension bridge with hinged style sling. We can get relevant parameters of hinged style sling VIV when it occurs vortex-induced resonance,and moreover,we can find out the maximum amplitude and the locked wind speed. And the conclusion has some engineering practical value for the actual engineering.Firstly,the paper established the single-cylinder two-dimensional model that flow around a cylinder and that the single-cylinder fluid–structure coupling two-dimensional model respectively refer to existing literature,and carried out the calculation of flow around a single-cylinder and calculation of single-cylinder fluid-structure coupling. We can get relevant reference quantity of the flow around a single-cylinder and of the single-cylinder fluid-structure coupling,and making a comparative analysis with the existing references. Thus the correctness of the fluid –structure coupling simulation method that used in this paper is verified;Secondly,the paper established and calculated the vortex-induced vibration response of the two side-by-side cylinders using the modeling method and the fluid-structure interaction simulation method in this paper under two different turbulence models(RNG ??- and SST ??- turbulence models),making a comparative analysis of the calculation results of the two different turbulence model and getting the corresponding conclusion : when calculated the vortex-induced vibration response of the two side-by-side cylinders,there exist some difference between the results of the two kinds of turbulent models, and the numerical simulation results of the SST ??- turbulence model are more close to the experimental value, and the SST ??- turbulence model is better than RNG ??- turbulence model;Finally,the paper established two cylindrical sling fluid-structure model of the long-span suspension bridge with articulated sling using modeling method in this paper,and carried out modal analysis of five different lengths of the sling(NO.D39、NO.D41、NO.D44、NO.D46 and NO.D49 sling) using the finite element software ANSYS to determine the natural frequencies of the sling and moreover to determine the stiffness and damping of the sling;Selecting three(NO.D39、NO.D44 and NO.D46 sling) of the five different lengths of the sling to carry out VIV simulation,calculated the vortex-induced vibration response of the three kinds of different length of the sling respectively,then we can get the locked wind speed,the maximum amplitude and etc. Then we can conclude that the locked wind speed of NO.D39、NO.D44 and NO.D46 sling increased in turn,however the locked wind speed of NO.D39 sling is much smaller than the locked wind speed of NO.D44 and NO.D46 sling. It indicates that NO.D39 sling is the easiest to make the vortex-induced vibration happen under the lower wind speed among the three kinds of slings. And it needs to be completed the vibration suppression measures in the actual project.