胶囊形气膜结构风致气弹响应及风振系数研究

Wind-induced aero-elastic response and vibration coefficients of capsule inflatable membrane structure

针对1/3矢跨比胶囊形气膜结构进行了气弹模型风洞试验,研究了结构的风致气弹响应变化规律,并给出了可供设计参考的风振系数。研究发现:结构平均变形呈迎风面凹陷,顶部隆起,横风向向外凸出的趋势,且这种变形趋势随着内压减小和风速增大越来越明显。0°风向角时的平均变形和振幅大于45°风向角时的平均变形和振幅大于90°风向角时的平均变形和振幅,结构合位移均值的极值出现在迎风面与顶面中心点;0°和45°风向角下,顶点竖向振幅>顺风向振幅>横风向振幅,结构以1阶模态振动为主;90°风向角下,顶点横风向振幅大于其他两个方向,结构以1阶和2阶模态叠加振动为主。各工况下结构的内压均有不同程度的减小。最后给出了考虑流固耦合效应的响应风振系数。

Aero-elastic model wind tunnel test is carried out for a 1/3 rise-span ratio capsule-shaped pneumatic membrane struc-ture,the characteristics of the wind-induced aero-elastic response of the structure are studied and the wind-induced dynamic vibra-tion coefficients for practical design reference are given.The research confirms that the averaged deformation of the structure shows a trend of windward depression,top uplift and outward bulge in the transverse direction.This deformation trend is increasingly ob-vious with the decrement of internal pressure and the increment of wind speed.The averaged deformation and vibration amplitude decrease when the wind direction ranges from 0°up to 45°,then to 90°,and the extreme value of structural mean total displace-ments tends to appear at the center points of windward surface and top surface.Under 0°and 45°wind directions,the sort of vibra-tion amplitudes of different components is vertical component,along-wind component and cross-wind component in descending or-der.Moreover,the structural vibration is dominated by the first-order mode.Under 90°wind direction,the amplitude of the cross-wind direction is greater than two other directions,and the wind-induced vibration is dominated by the superposition of the first and second order modes.The internal pressure of the structure decreases in different extents under all cases.The response-based wind-induced dynamic vibration coefficients considering the fluid-structure interaction effect are given.