单层平面索网幕墙结构的风激动力性能研究

Wind-induced dynamic performance of cable net glazing

为深入了解单层平面索网玻璃幕墙结构的风激动力性能,采用基于随机振动理论的模态叠加频域方法进行了单索幕墙结构的风振响应分析.由于单索幕墙具有较高的几何非线性,又将模态叠加频域分析方法的计算结果和非线性时程分析方法的精确计算结果进行了比较,证明了该方法的准确性.同时,采用各阶模态应变能的大小分析了各阶模态对单索幕墙结构风振响应的贡献,得到脉动风荷载下结构的振动以第一阶模态为主的结论.

Because of the single-layer plane cable net glazing＇s characteristics of weak stiffness, light weight, small damping and low frequencies, the single-layer plane cable net structure is sensitive to the fluctuating wind. However, research on wind-induced dynamic performance of this kind structure is scarce. Mode superposition method based on random vibration is used in the wind-induced response analysis of a structure. Because of the single-layer plane cable net＇s high geometric nonlinearity domain method＇s linearity hypothesis, we have compared the results of and the mode superposition frequency frequency domain method and the accurate nonlinear time-history method, and the accuracy of frequency domain method is proved. At the same time we analyzed the contribution of all modes to the wind-induced vibration by the strain energy of every mode and obtained the conclusion that the dynamic vibration of the single-layer plane cable net structure is mainly decided by the fist mode under fluctuating wind.