小垂度薄膜屋盖的气弹动力耦合作用方程

薄膜结构自重轻、刚度小、自振频率低,对风的作用非常敏感,一般认为在风荷载作用下会产生较大的位移和加速度反应,并可能引起局部流场的变化甚至诱发气弹失稳,所以应在考虑风与结构的耦合作用基础上分析结构的风振反应。研究了风与薄膜屋盖的耦合作用方程。从弹性薄壳的无矩理论出发,考虑薄膜结构的几何非线性,并引入扁壳理论的假定建立了小垂度薄膜屋盖的平衡方程和相容方程。然后采用流体力学中的势流理论并参考空气动力学中的薄翼型理论确定了作用于封闭薄膜屋盖外侧的动气压,从而建立了风与薄膜屋盖的动力耦合作用方程。为下一步的研究提供了解析模型。

THE WIND-STRUCTURE INTERACTION EQUATION OF MEMBRANE ROOFS WITH SMALL SAG

With light mass, small stiffness and low natural vibration frequency, membrane roofs are sensitive to wind. Generally, wind loading may induce large displacement and acceleration of membrane roofs, which may result in the change of local flow field around the structure and even induce the aeroelastic instability. Therefore, the wind-induced vibrations of such structures should be analyzed on the basis of considering the wind-structure interaction. The wind-structure interaction equation of membrane roofs is studied in this paper. The equilibrium equation and the compatible equation of membrane roofs are obtained by applying the membrane theory of thin shallow shells in which the geometrical non-linearity of the structure is taken into account. The potential flow theory in fluid mechanics and the thin airfoil theory in aerodynamics are adopted to define the aerodynamic pressure on membrane roofs. Thus, the wind-structure interaction equation of membrane roofs is established.