大跨度结构三维随机脉动风场的模拟方法  

SIMULATION METHOD FOR 3-D STOCHASTIC WIND FIELD AROUND LONG-SPAN STRUCTURES

作　　者：罗俊杰[1] 韩大建[1] 

机构地区：[1]华南理工大学土木工程系,广州510640

出　　处：《振动与冲击》2008年第3期87-91,共5页Journal of Vibration and Shock

基　　金：广州市科技攻关项目(2004Z3-E0351)

摘　　要：对大跨度空间结构进行风荷载动力时程分析,首先需要获得不同节点在不同紊流方向上的脉动风速时程。在传统一维多变量谐波合成法的基础上,考虑了紊流风速在不同节点和三个方向上的相关关系,并且引入了水平风速的相位差,提出三维多变量随机脉动风速场的模拟模型。同时,利用FFT技术来代替谐波叠加的算法,以提高谐波项合成效率。通过一个算例表明模拟样本的谱密度函数、相关函数和概率统计参数与目标结果吻合得很好。这说明所提出的模型可以准确地模拟出适合大跨度结构的三维多变量随机脉动风场。The non-linear time-domain dynamic response analysis of the long-span structures subjected to wind load can be carried out according to the time history of wind velocity. To describe the natural wind velocity field precisely, a 3-dimensional multivariable model based on the spectral representation method is deduced by considering the correlations between three turbulent wind components at different points. The phase angle is introduced to represent the time delay in wind velocity passage. The FFT technique is applied, instead of wave superposition, to decrease the time consuming.The results generated by the new model shows that the cross-power spectral density function, cross-correlation function and probabilistic statistic parameters are in good agreement with the expected targets. It means the proposed method can simulate the target stochastic wind velocity field accurately and effectively.

关 键 词：MONTE Carlo模拟方法 随机过程 相干函数 FFT技术 时域分析 

分 类 号：P315.69[天文地球—地震学] TU351[天文地球—固体地球物理学]