基于特征正交分解的桥梁风场模拟  

Digital Simulation of Bridge Wind Fields Based on Spectral Repre-sentation Method with Proper Orthogonal Decomposition

作　　者：胡亮[1] 李黎[2] 樊剑[2] 

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092 [2]华中科技大学土木工程与力学学院,武汉430074

出　　处：《武汉理工大学学报（交通科学与工程版）》2008年第1期16-19,共4页Journal of Wuhan University of Technology（Transportation Science & Engineering）

基　　金：交通部西部交通建设科技项目资助(批准号:200431800024)

摘　　要：推导出了随机过程特征正交分解计算公式.为提高原型谱表示法的计算速度,将特征正交分解的强形式,即基于功率谱矩阵的随机过程特征正交分解(SPT)引入到谱表示法中,代替原有的对功率谱矩阵的Cho lesky分解,并给出了实用的模拟公式.该算法可用FFT加速.结合模态截断技术,POD的引进可节省谱表示法模拟的计算量.通过算例,定义了风的吹动模态,说明了风场SPT的明确的物理意义,同时模拟方法的有效性亦得到验证.Nowadays,original spectral representation method is the most popular method for Monte Carlo simulation of bridge turbulence wind velocity fields.Principal components of stochastic vector process can be extracted by utilizing another generalized method called proper orthogonal decomposition（POD）.Rigorous theoretical descriptions of these methods are given.To improve simulation efficiency of the spectral representation method,POD based on power spectral density matrix of stochastic vector process,which is the so called spectral proper transformation（SPT） technique,is employed to replace the Cholesky decomposition.Practical algorithm is put forward and its efficiency can be enhanced by FFT also.Combining with the modal truncation technique,significant reduction of the computational cost can be expected.Finally,two numerical examples are included,by which this presented approach is validated.＂Wind blowing mode＂ is also defined vividly by the examples,accompanied with clarification of the clear physical sense of POD.

关 键 词：风场模拟 谱表示法 特征正交分解(POD) 

分 类 号：U448.3[建筑科学—桥梁与隧道工程]