Wind-induced Effect Analysis Of Long-span Shell Grid Structure

Over the years,frequent wind disasters have deformed and even destroyed the structures of many long-span buildings used in industry.Due to the characteristics of light weight,large flexibility and dense frequency distribution of long-span double-layer grid structure,it is easy to respond to wind load,which seriously affects the development of industry.The important reference basis for structural design is the shape factor and wind vibration coefficient of the structure.In addition,due to the large number of long-span structure members and complex shape,as well as the fact that all the relevant parameters of complex structure design are not covered in the national code,there is often a lack of reference basis in structural design.Therefore,it is necessary to study the wind resistance design of long-span spatial structure.On the background of practical engineering,this paper adopts the numerical simulation(CFD)method with lower cost and higher efficiency to study the wind resistance design of long-span grid structure with skylight and long-span dry coal shed grid structure.Wind resistance design of long-span spatial structures mainly includes two aspects: partial pressure distribution analysis and wind vibration response analysis.The specific work content of this paper is as follows:(1)Based on the interface development program of STADS and Fluent,the partition model of the grid structure with skylight was established,the numerical wind field calculation domain was generated and the calculation results were output,which greatly improved the calculation efficiency,finally,the wind pressure distribution law of the corresponding structure is summarized by comparative analysis and the shape coefficient is given;Through the comparative analysis of the wind pressure distribution under the two conditions of the structure skylight opening and closing,it is found that the overall wind pressure distribution of the two structural forms is the same,but some parts are different.The structure window opening can effectively reduce the overall wind pressure value and reduce the wind suction force received by the grid structure,but it will increase the pressure at the bottom of the structure and increase the reaction force of the structure support.Attention should be paid to the structure design.(2)Through the analysis of wind vibration response of dry coal shed grid structure from different angles of frequency domain and time domain,the wind vibration coefficient of structural displacement is summarized and compared.In the frequency domain,based on the random vibration module of Ansys software PSD,considering the influence of vibration modes on the displacement results,combined with the results of high-order vibration modes to determine the value of vibration modes,the wind vibration coefficient of structural displacement is given,and the comparative analysis is carried out under different wind angles;In the time domain,the STADS series software was used to calculate the time history of wind vibration,and the corresponding time history data results were obtained by automatic loading.Finally,the partition displacement wind vibration coefficient diagram of the structure was given,the variation trend of displacement wind vibration coefficient under different wind directions was summarized,and the position of the structure with high degree of influence by fluctuating wind was analyzed;Finally,comparing and analyzing the data results obtained by the two methods,it is found that the variation trend of wind vibration coefficient is basically the same,only the numerical value is different.The reasons for the difference between the two methods are summarized,and the two calculation results can be used as reference for structural design.