基于双POD模型的大跨屋盖多模态随机风致响应研究

Three-dimensional numerical simulation of spatial-correlated stochastic wind field based on double POD model

讨论了具有空间相关三维随机风荷载的数学模型。风荷载的准确模拟是结构进行风致动力响应分析的第一步,POD法提供了一种高效、准确的风荷载模拟方法。本文根据双POD模型和Monte Carlo模拟法,详细研究了空间相关三维风场的数值模拟方法,模拟的风场与实际较为一致。结合随机离散法和多阶模态加速度法的原理,详细推导了大跨屋盖风致响应与风振系数的计算方法。通过大跨屋盖刚性和气弹模型风洞试验,得出高阶振型对大跨屋盖结构的风致响应的贡献不可忽略,并计算了屋盖的风致动力响应时程。研究了大跨屋盖表面荷载风振系数和位移风振系数的分布,结果与有限元分析较为吻合,证实了本文提出的方法是一种高效、准确的大跨屋盖风致响应计算方法。

studied in this the analysis of The mathematical m paper. The modeling odels of spatial-correlated wind velocity stochastic processes and simulation of the wind field along structures is a fundame have been ntal step in their wind-induced dynamic response. The proper orthogonal decomposition（POD） technique offers efficient and accurate tool to simulate the fluctuating components of wind fields. Based on double POD model and Monte Carlo framework, a very efficient simulation scheme for turbulence components is pro- posed. Utilizing the Random Discrete theory and the multi-modal acceleration method, schemes for estimating the wind-induced dynamic response of long-span roofs are presented. Through wind tunnel tests of the rigid and aeroelastic models, the dynamic responses of long-span roof are analyzed in the time domain. Analytical results show that the contribution of higher vibration modes can not be ignored. The distribution of gust load factor and gust displacement factor on roof surface has been studied and compared, respectively. The analytical results have good agree with that by the finite element method. Practically, the procedure presented in the paper can be an accuracy and effectiveness method to estimate the dynamic response of longspan roofs.