Study On The Field Measurements Of Wind Characteristics And Wind Induced Responses Of Open Grid Space Structure With Leaf Shape

Large-span spatial structure is wind sensitive structure, wind loads and wind-induced vibration is the main factor controlling the safety of structural. In recent years, as China’s economic and technological growth, large-span spatial structures are more and more applied to the modern engineering. But some large-span spatial structures damaged under wind load. So, wind resistant design of large-span spatial structures caused more and more attention of engineers.The analyses data of this paper comes from wind loads measured from the Wuxi Grand Theatre with opened leaf shape. Real-time wind load on roof information was measured through 12 pair wind pressure sensors installed on the roof, and record the flow data with anemometer.Based on actual measured wind data, calculating the wind speed spectrum and turbulent intensity, study finds wind velocity spectrum ordinate at different times are slightly different, but the overall variation is consistent. Compared with the Davenport spectrum, Von Karman spectrum and Kaimal spectrum, At low frequencies, measured wind speed spectral curves was fairly consistent with classical spectrum curve, but quietly different at high frequency band. The ground roughness(design values calculated by the class B) has been changed due to the impact of new construct buildings on the site, measured wind turbulence intensity is located in between the C and D classes, closed to the turbulent intensity of class Ⅳ landforms in Japanese code,So the effects of late construction to the ground roughness must taken into account during the Architectural design phase, otherwise may cause adverse effect in the building.Spectrum of measured wind pressure characteristics was researched, Correlation coefficient between measurement points and the change rule of wind pressure coefficient correlation in the vertical direction was investigated in this paper. Absolute value of the correlation coefficient between measurement points are less than 0.2, which belongs to the weak correlation. One reason is the large distance between measuring points, less air convection caused by roof does not leak; The other is that the measuring points mainly located in the middle of the roof, relatively long distance from eaves, corner region with complex wind pressure distribution.Peak factor is calculated by Peak Factor Method, Hermite Series Method and sadek-simiu Method, compared the difference of results obtained by three method and peak factor ranges, and peak factor’s recommend values of this kind of open space grid structures was given.The probability density curve and statistical parameters of measured wind was analyzed. Compared with the standard Gaussian probability density curve, measured wind probability density curve has good symmetry, only slightly higher than standard Gaussian curve at the tail of the curve. The measured wind pressure deviation and kurtosis is less than wind tunnel test results, non-Gaussian characteristics of measured wind pressure are not obvious. Non-Gaussian wind pressure regional division was proposed based on probability and statistics parameters, as well as the relationship between skewness and kurtosis curves, wind pressure time history was simulated by Yamazaki-Shinozuka method and the Forrst-Gurley method, the simulated wind power spectra were in good agreement with the measured spectrum, skewness and kurtosis parameter which indicates of Non-Gauss characteristic are within a reasonable margin of error.Based on the measured vibration velocities, structural natural frequencies and vertical modal was obtained by random decrement method, peak picking method and frequency domain decomposition method, compared with the finite element calculation result, both natural frequency error is below 10%, and the measured vertical mode are in good agreement with the finite element results. Using polynomial fitting method to remove the trend data, we get the integrated displacement signal, analysis of the signal shows the vibration is slight and periodical.In this paper, we made comprehensive research on wind-induced response and wind load characteristics of large-span structure based on on-site measurement method. Research results can enrich the knowledge of wind effects on large span structure and wind-resistant design method, provide scientific references for the design and construction of large-span buildings.