基于随机Fourier谱的风场仿真

Simulation of Wind Field Based on Stochastic Fourier Spectrum

研究了由随机Fourier谱生成具有特定场地风荷载统计特性的样本函数的问题.首先对随机风场模型进行了描述,然后利用谐波合成的方法,在对互随机Fourier谱矩阵进行Cholesky分解的基础上,通过一组余弦函数的和对随机脉动风速场进行了模拟.最后,结合一20层平面框架结构纵向风速场的仿真问题进行了数值仿真研究.算例表明,所提算法可以准确地模拟给定场地特性的脉动风速时程.

Research was made on generating sample functions with prescribed statistic characteristics of wind loads at a given site. First, the random wind field model was described. Then based on the har- monic-wave superposition method, the random turbulent wind speed field was simulated by superposing a set of cosine functions after the cross stochastic Fourier spectrum matrix was decomposed with Cholesky＇ s method. Finally, an example involving simulation of longitudinal turbulent wind field of a 20-story plane frame structure was investigated. The result shows that the proposed algorithm is of accuracy.