高层建筑风场的脉动风速时程模拟

采用经过FFT算法改进的谐波叠加法(WAWS)及自回归(AR)模型的线性滤波法对实际工程进行脉动风速时程模拟.对2种算法所模拟的风速时程进行分析,结果显示了风速功率谱及相关函数的特性,分析结果说明AR模型中模型阶次及时间步长对风速时程产生较大影响.根据结构的有限元动力分析,采用能量相等的原则,即使结构固有频率段内的目标谱和模拟谱能量相等,对风速时程进行修正,使模拟风速时程更趋合理.

Simulation of time history of turbulent wind speed in wind field around high-rises

Time history simulation of turbulent wind speed near an actual building was conducted by using the weighted amplitude wave superposition(WAWS) method improved with FFT algorithm and the linear filtering method of auto-regression(AR) model.The time history of the wind simulated with the two algorithms was analyzed.Its result has manifested characteristics of power spectrum of the wind and its correlative function.It also showed that the model order as well as the time-step of the AR model had a greater influence on the time history of the wind speed.According to finite element dynamic analysis and employing energy equality principle to make the energy of both the objection spectrum and simulated spectrum equal,the time history of the wind speed was revised to make the simulated time history of the wind speed more reasonable.