Study on aerodynamic effect uncertainty for large span roofs

The aerodynamic effect uncertainties for two kinds of typical large span roofs, a spherical shell and a cylindrical shell were analysed systematically based on repeated wind tunnel tests and the probability plot correlation coefficient method. Probability distribution characteristics of mean wind pressure and fluctuating wind pressure were investigated. The study indicates that normal distribution is the ideal model to describe the probability distribution of mean wind pressure coefficients. The mean value of variation of mean pressure coefficients for the spherical shell and the cylindrical shell are 0.11 and 0.13, respectively. Lognormal distribution is the ideal model to describe the probability distribution of fluctuating wind pressure coefficients. For the spherical shell, the mean value of fluctuating pressure coefficients at the leading edge and downwind part are relatively high, and the maximum value occurs at the leeward edge. The maximum value of standard deviation occurs at a 45° angle to the incoming flow. For the cylindrical shell, both the mean value and standard deviation of fluctuating pressure coefficients reach the maximum at the joint area of the rooftop and the side walls. Monte Carlo method is carried out to investigate the influence of sample size on the sampling error of mean wind pressure coefficients. Adjusting factor related to the variation of mean pressure coefficients and sample size is proposed, which will provide references for current wind tunnel tests.