单层平面索网幕墙结构的风振响应分析及实用抗风设计方法

Wind-induced response analysis and practical wind-resistant design method of cable net glazing

单层平面索网玻璃幕墙结构是广泛应用于大型公共建筑中的一种新型结构形式,由于其具有柔性大、质量轻、阻尼小、自振频率低的特点,属风敏感结构。由于单索幕墙具有较高的几何非线性,本文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。将模态叠加频域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。并且本文通过分析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。根据该结论本文采用频域方法推导了单索幕墙结构的位移均方差和索内力均方差的实用计算公式,同时考虑单索幕墙的结构特点提出了基于结构响应的单索幕墙结构实用抗风设计方法。

Because of its character of weak stiffness、light weight,small damping and low frequencies,the single-layer plane cable net structure is sensitive to the fluctuating wind.And mode superposition method based on random vibration is used in the wind-induced response analysis of the structure.Because of the high geometric nonlinearity of the single-layer plane cable net and the linearity hypothesis the mode superposition frequency domain method,we have compared the results of frequency domain method and the accurate nonlinear time-history method,and the accuracy of frequency domain method is proved.Furthermore,we analyzed the contribution of all modes to the wind-induced vibration and concluded that the dynamic vibration of the single-layer plane cable net structure is mainly decided by the first mode under fluctuating wind.According to the above conclusion we deduced the practical calculation formula of the displacement variance and cable tension variance,at the same time we brought forward the practical wind-resistant design method of the single-layer plane cable net based on the structural response.