Wind Pressure Field Model And Wind Vibration Response Analysis Of Aluminum Alloy Spherical Reticulated Shell Structure

Due to the advancement of society and the needs of human development,people are pursuing the construction of a spatial structure with a large coverage area.In this context,the large-span aluminum alloy reticulated shell structure has been applied more and more because of its unique advantages.The domestic engineering examples include Shanghai Chenshan Botanical Garden Greenhouse,Yiwu Swimming Hall,etc.These structures are light in weight and soft in flexibility.The wind load acting on the surface will exhib it characteristic turbulence,so the wind load will become its main control load.At present,the research on wind-resistance design of high-rise structures is more in-depth,and the theory is relatively mature.However,the development of long-span structural wind engineering is relatively slow,and no representative calculation methods are given at home and abroad.This paper base on the research work of scholars at home and abroad,takes the large-span aluminum alloy spherical reticulated shell of rise-span ratio is 1/6,1/3 and 1/2 as an example,systematically studies the pulsating wind characteristics of surface of the spherical reticulated shell.Wind vibration response and response calculation method.The main work content and results of this paper are as follows:(1)Calculate wind pressure coefficient and draw contour map based on wind pressure time history data of wind tunnel test.It is found that the wind pressure coefficient increases synchronously with the increase of the spherical rise-span ratio.Although the average wind and pulsating wind are roughly synchronous on the surface of the spherical reticulated shell,the difference in distribution pattern increases with the increase of the rise-span ratio.(2)Improved single parameter pulsating wind pressure spectrum engineering model which proposed by Suning,present a high accuracy single parameter pulsating wind pressure self-power spectrum model which suitable for spherical reticulated shell structures,and a two-parameter coherent function model with high accuracy was proposed based on MATLAB,So can obtain the pulsating wind pressure cross-power spectrum model(3)Combining the existing results of the virtual excitation method with the principle of the harmonic excitation method,the excitation covariance matrix can be calculated by the harmonic excitation method and the modal contribution coefficients of each order are further calculated.Finally use MATLAB compile the harmonic excitation method procedure with automatically select modals for calculation.It is found that the method is relatively accurate and the calculation speed is fast.is a simple and rapid windoscillation response algorithm.(4)The response wind-induced vibration coefficient of the spherical reticulated shell of rise-span ratio is 1/6?1/3?1/2 is studied:When the research object is the displacement wind vibration coefficient,the spherical reticulated shell can be divided into two cases.When the rise-span ratio is greater than 1/3,the displacement wind vibration coefficient increases with the increase of the rise-span ratio,When the rise-span ratio is less than 1/3,the displacement wind vibration coefficient decreases with the increase of the rise-span ratio;when the research object is the internal force wind vibration coefficient,its value increases with the increase of the rise-span ratio.In addition,the consistent wind-induced vibration coefficients calculated by different methods vary greatly.It can be seen that how to determine a reasonable and accurate standard method for calculating the consistent wind-induced vibration coefficient requires further research by relevant scholars.(5)The finite element model of aluminum alloy and steel spherical reticulated shells with the same cross-section and rise-span ratio of 1/2 was established by ANSYS and the corresponding response wind-induced vibration coefficients were calculated.The results show that although the aluminum alloy reticulated shell structure is softer than the steel reticulated shell structure,But the wind-induced vibration coefficients of the two are basically consistent.Therefore,the change of building structural material does not necessarily change the wind vibration coefficient.Only when the fundamental frequency of the steel ball shell structure is close to the frequency of the load,changing the steel structure to the aluminum alloy structure at this time will result in a smaller fundamental frequency,a stronger resonance response,and an increase in the wind vibration coefficient.On the other hand,if the fundamental frequency of the structure is still far from the load frequency after the material is changed,the wind vibration coefficient will not change.