矩形平面投影气膜结构风振响应特性及风振系数研究

Wind⁃induced vibration response characteristics and coefficients on inflatable membrane structures with rectangular⁃planed projection

近年来,矩形平面投影气膜结构被广泛应用于大跨度气膜煤仓等设施中,但是规范中尚无该类结构的风振系数。本文通过风洞测压试验,测量了典型矢跨比矩形平面投影气膜结构的风荷载;运用非线性动力时程分析法分析了结构的风振响应。研究了风速、风向、跨度、矢跨比和内压等参数对结构变形和响应极值的影响。结果表明:结构呈现迎风面及背风面凹陷、顶部和两侧向外凸的平均变形特征;极值响应的分布受结构参数和风向角的影响;响应的大小与跨度和矢跨比呈正相关;增大内压在一定程度上可以提高结构的抗风性,内压调控区间建议为400~500Pa;给出了可供抗风设计参考的位移风振系数及应力风振系数。

In recent years,inflatable membrane structures with rectangular planes have been widely used in large-span coal bunkers and other facilities.However,the wind-induced vibration coefficients for these structures are not provided in design standards.In this paper,the wind loads on inflatable membrane structures with rectangular planes for typical rise-span ratios are obtained through wind tunnel tests.The wind-induced responses are calculated via a nonlinear dynamic time-history analysis method.The influences of different parameters such as wind velocity,wind direction,span,rise-span ratio,and internal pressure on the deformations and extreme responses are investigated.The results show that the mean structural deformation is characterized as concave on the wind⁃ward and leeward regions and convex on the top and side regions.The spatial distributions of extreme responses are significantly in⁃fluenced by the structural parameters and wind directions.Additionally,the wind-induced responses are positively correlated with the spans and rise-span ratios.The structural wind resistant performance can be strengthened by enhancing internal pressure to some extent.The internal pressure is recommended between 400 and 500 Pa.The wind-induced vibration coefficients of displace⁃ment and stress are provided for engineering reference.