塑料大棚结构的脉动风速与风压时程模拟

Numerical Simulation of Pulsating Wind Velocity Histories and Wind Pressure Histories of Plastic Greenhouse

作用在塑料大棚结构上的主要动力荷载是风荷载,考虑脉动风作用的塑料大棚结构风振响应能真实地反映结构的受力特点。为了对塑料大棚结构进行时域内风振响应分析,必须解决脉动风速时程模拟问题。为此,采用谐波叠加法对塑料大棚结构表面的脉动风速进行模拟,获得不同空间点的风速时程曲线,对比了模拟功率谱与目标功率谱的变化趋势,分析了不同空间位置的相干性随两点距离增加的变化规律,模拟了不同点的脉动风压,从而为研究塑料大棚结构风振响应提供了荷载条件。

The wind load is important dynamical load of the plastic greenhouse structure. The wind vibration response of the plastic greenhouse with fluctuating wind can accurately reflect the force characteristics of the structure. Wind-induced vibration response analysis needs to obtain the data of fluctuating wind loads. In this study, the samples of the fluctuating wind speed for surface of the plastic greenhouses structure were simulated by using the harmonic superposition method, and the wind velocity time histories in different space positions were obtained. The variation trend of simulation power spectrum was compared with the target power spectrum. The variation of the coherence of different spatial positions with the increase of distance between two points was analyzed. Finally, the fluctuating wind pressure of different points are simulated, and provide the inputting data for the study of wind vibration response of plastic greenhouses.