Uncertainty Analysis Of Wind-Induced Structural Response On Low-Rise Building

Low-rise buildings are easily destroyed by hurricanes for their own characteristics like light weight and small stiffness. They are often distributed in coastal areas which are subjected to hurricanes frequently and thus their wind-induced damages and even collapses and casualties caused by them are causing huge losses. Given the shortcomings of current design method, uncertainty of structural extreme response induced by wind load is researched so as to provide a better basis for reliability design. The main work done in the paper are as follows:(1) The characteristics of wind pressure on the roof of the low-rise building are firstly investigated. Based on related structural design codes and shape features of this building, a steel frame structure model is preliminarily designed and then the design process is presented through purlin design. Subsequently, its finite element model is built and optimized by using structure design software, and then the time history analysis is implemented after importing processed experimental wind pressure data.(2) Based on the column axial forces data extracted, the extreme value distribution is studied, so are the probabilistic models of skewness and kurtosis and the function relationship between them and parameters of the extreme value distribution. Then the joint probability distribution is calculated. Finally, considering the probability characteristic of mean and standard deviation of response data, the uncertainty of extreme response is calculated and analyzed under the specific quantile.The results show that:(1) Wind pressure on the roof are largely negative and has non-Gaussian features. Also, structural response has non-Gaussian features and extreme value distribution can be fitted well using the Hermite model. It is also found that skewness and kurtosis respectively follow normal distribution and lognormal distribution, and the empirical model can be a good description for the above-mentioned function relationship.(2) Considering the first four moments of structural response simultaneously, the distribution of the extreme value response under a specific fractile is built. Take the bottom column for example, the confidence interval of the extreme axial force is (27.00,34.70)kN under the confidence level of 90%, whose coefficient of variation is about 8%.