Fluctuate Wind Velocityhistories Simulation And Flow-Solid Coupling Research Of Gantry Crane

The gantry crane is increasingly becoming large-span structure, which belongs to the wind-sensitive structure.because of it’s flexibility and low natural vibration frequency, this structure tends to large vibration and deformation underthe incentive function of the wind,and produces high flexibility and strong nonlinearity,so wind load is the critical factorfor the structural design.In the design of the crane, the wind load is not only the important load of the structural stress analysis, but also the main basis for the calculation of the motor power and the stability analysis of the gantry crane.However, the research on the wind engineering of crane is still weak, and the description of the wind load in<the crane design standard GB/T3811-2008> (hereinafter simply "standard" for short) is relatively simple.With a large gantry crane as the prototype and the aid of the structural finite element analysis software AYSYS, mathematical software MATLAB, fluid dynamics software CFX and FLUENT,This paper researchs the correspondence between the static load calculation parameters and the dimension of the crane structure,and the coupling dynamic characteristics of structures under wind field.The main contents and results are as follows: 1.Reference to the wind engineeringtheory in the field of bridge,by Monte Carlo method and Shinozuka harmonic superposition method,using Davenport spectrum to simulate the time history of wind speed and wind pressure,then studying on dynamic response of portal crane by fluctuating wind with the finite element analysis software of ANSYS,this paper compared the results of static load calculation and the time history curve of speed spectrumanalysis under two conditions of working state and non working state.The results show that the stress and displacement of the structure with considering the effect of wind are larger than that of the traditional static load.Especially in the working condition, the fluctuating effect of the wind will have a larger vibration excitation to the flexible main beam structure under the working load, which will lead to the increase of the vibration amplitude of the main beam.Under the non working condition, the fluctuating effect of the wind under the larger wind pressure value affects the stability of the crane.2.With the method of computational fluid dynamics (CFD) and CFX software, this paper calculated the wind load through simulating 80 sets of large double girder gantry crane model and numerical wind tunnel.The Calculation results brought out the corresponding relationship between the body shape coefficient and wind reduction coefficientand the structure size of the double beam structure with different aspect ratio,high aspect ratio,interval ratio.And the results enriched the content of the "standard".By comparingresultsof the "standard",foreign research and the numerical analysis, the applicability of the numerical simulation methodis verify, and the "standard" values larger than numerical simulation values and foreign research results.3.On the platform of ANSYS Workbench, combining with fluent system coupling module and using the two-way coupling method,the papernumerically simulated the crane wind vibration response. The caculation results showed the crane pressure contours and displacement curve,and validated the bidirectional coupling method in crane research on the crane wind vibration effect.Then results were compared with the traditional static load caculating methodand the transient analysis results with simulating wind speed spectrum.In this paper, the static load and dynamic response of the gantry crane are studied in three ways, and the effect of the wind load on the stress and displacement of the crane structure can be more accurately quantified.The results reveal that the "standard" to determine the wind load in the large shape coefficient is too conservative, but obvious vibration effect caused by wind load did not get enough attention.