Research On Wind-induced Vibration Of Portal Frame Of Gantry Crane

As a large-scale material handling tool,gantry cranes are mostly located in workplaces that are susceptible to strong winds,such as ports,freight stations,and coastal waters,and they are showing a trend of being taller and lighter.The changes of the crane are becoming more and more sensitive,so the research on the wind-induced vibration of the crane structure has high engineering significance.The vortex-induced vibration is a common form of windinduced vibration of the gantry crane structure under the action of the incoming wind,and it is also one of the important factors influencing the fatigue damage of the crane structure.Therefore,this paper uses the UDF function of the Fluent software to compare high quality Numerical simulation of two-dimensional single-degree-of-freedom transverse vortexinduced vibration of cylindrical,square,rectangular,and tandem square columns.Firstly,perform numerical simulation of the flow around the cylinder,square column and rectangular column to obtain the drag coefficient,the root mean square of the lift coefficient and the Strouha number of the structure under different Reynolds numbers,and compare the results with the experimental results and numerical simulation results of others.The accuracy of the results and the feasibility of using the finite volume method to simulate the bluff body turbulence problem are verified.The results show that the aerodynamic coefficient of the cylinder has a high Reynolds correlation,while the square and rectangular columns are bluff structures with sharp corners,and the boundary layer separation points are determined,so the Reynolds correlation of the aerodynamic coefficients is low.Secondly,referring to the design drawings of the gantry crane,establish high-quality square columns,cylinders and rectangular columns to conduct two-dimensional single-degreeof-freedom transverse vortex-induced vibration numerical simulation.By comparing the structural amplitude,frequency ratio and wind speed in the lock zone,the wind-induced vortex-induced vibration The evaluation of wind resistance in terms of vibration explained that the wind speed in the workplace should be referred to in the design process of the gantry crane to avoid the occurrence of the locked area,that is,the occurrence of resonance.Then the characteristics of the flow field are analyzed,and the vortex detachment forms of the three structures are explained.Finally,the numerical simulation of the flow around the tandem square columns with different spacing ratios is carried out.According to the calculation results and the characteristics of the flow field,the tandem structures with different spacings are roughly divided into three modes.Then refer to the crane design drawings to establish high-quality ratio tandem square column models in different modes and perform single-degree-of-freedom vortex-induced vibration numerical simulations and compare their amplitude,frequency ratio and flow field characteristics.The results show that there are great differences in the vortexinduced vibration response of tandem square columns in the three modes.Therefore,the wind resistance of the tandem structure under different modes should be considered in the crane design process,and the tandem structure with an appropriate spacing ratio should be selected.This article has done a more comprehensive study on the single degree of freedom transverse vortex-induced vibration of the high-quality ratio structure,in order to provide a reference for the design of wind-resistant and load-reducing gantry cranes.