Research On The Wind Pressure And Its Correlationship Of A Stadium Cantilever Roof Structure

The domestic and abroad wind-resistant research on large-span roof structures ismainly concentrated in some simple forms. It still does not have a unified researchmethod for the annular cantilevered roof structures, and the Codes of many countriesalso has not given specific wind design bases. By means of the wind tunnel test andnumerical simulation, an in-depth study is made on the cantilevered roof of stadium inChenzhou City to provide a useful reference for the project design. The study includeswind pressure characteristics, fluctuating pressure correlativity and wind-inducedresponse, and content is as follows:Firstly, the simultaneous wind tunnel test and numerical simulation are carried outto get wind pressure date. The characteristics of mean wind pressures under the typicalwind directions are studied. The results show that the negative pressure is very widelydistributed at the outer and inner surface of the roof, and the value of net wind pressureat the saddle-shaped raised area is large. Compared with the results of the wind tunneltest, the results based on RNG k-ε and Realizable k-ε turbulence model are in goodagreement with those of the wind tunnel test, and the numerical simulation results at theouter surface are better than those at the inner surface.Secondly, based on the data of the wind tunnel test, frequency domaincharacteristics is detailedly studied, and a new mathematical model of wind pressurespectrum of the cantilevered roof is established. The correlativity coefficient andcoherence function of along-wind and across-wind points are analyzed to get thecharacteristics of the external fluctuating pressure correlation of the stadium’scantilevered roof. What’s more, the coherence function curves of along-wind andacross-wind points are fitted by the Davenport coherence function formula. Theresearch shows that affected by wind direction and points’ position, the spectrum curvesof wind pressure are mainly controlled by atmospheric turbulence in the low frequencyand controlled by vortex shedding in the high frequency. The correlativity is greatlyimpacted by position and arrangement of measuring points.Finally, according to the time histories of wind pressure obtained from the windtunnel test, the wind-induced response of this cantilevered roof structure is calculatedusing time-history method. The average, root mean square and peak value of bothdisplacement response and axial force response are detailedly analyzed. What’s more, the most unfavorable wind direction is determined. The wind vibration coefficients ofboth displacement and axial force have the same effect, and the values are mainlybetween1.5and3.5. As the reference of structural wind resistant design, theseconclusions have demonstrated an important role of the fluctuating wind effect.