考虑流动分离时薄膜结构的气弹稳定分析  

ANALYSIS OF AEROELASTIC INSTABILITY OF MEMBRANE STRUCTURES CONSIDERING THE FLOW SEPARATION

作　　者：刘瑞霞 刘春宇 

机构地区：[1]中国建筑工业出版社,北京100037 [2]山东聊城发电厂,聊城252000

出　　处：《钢结构》2008年第6期32-36,共5页Steel Construction

基　　金：国家自然科学基金资助项目(50338010)

摘　　要：研究均匀的理想来流作用下,小垂度矩形双曲抛物面薄膜结构的气弹失稳临界风速;考虑气流在薄膜结构前缘的分离形成漩涡,在风与薄膜结构之间以及尾流中引入无限薄的漩涡层;考虑风与结构之间存在的流固耦合作用,应用流体力学中的势流理论和空气动力学中的升力面理论确定作用于薄膜表面的气动力,从而建立起薄膜结构的气弹动力耦合作用方程。由于此耦合作用方程为带有积分的微分方程,很难得到解析解,利用Bubnov-Galerkin近似方法将其转化为一常系数二阶微分方程,根据Routh-Hurwitz稳定性准则确定薄膜的失稳临界风速。由临界风速公式可以看出,临界风速与膜材参数、薄膜结构的几何尺寸和形状以及两个方向上的预张力有关。最后,对临界风速的影响因素进行参数分析,得到一些结论。The instability critical wind velocity of a hyperbolic parabolic membrane structure with rectangular plane under the action of uniform ideal potential flow is studied. Considering the flow separation at the sharp edge of the structure, an infinitesimally thin vortex sheet is introduced between wind and the structure and also in the wake. The aerodynamic interaction equation of the membrane structure is established based on the aerodynamic force determined by applying the potential flow theory and the lifting-plane theory in which the wind-structure interaction is taken into account. Because the integral-differential interaction equation is too complicated to get the analytical solution, Bubnov-Galerkin approximate method is applied to transform it into a second order linear ordinary differential equation; and Routh-Hurwitz stability criterion is used to determine the instability critical wind velocity. The formula shows that the critical wind velocity is relevant to the material, size and shape of the structure, and the pretension forces in two principal directions. Finally, some important conclusions are obtained from parametric analysis.

关 键 词：薄膜结构 气弹动力失稳 流固耦合作用 临界风速 

分 类 号：TU38[建筑科学—结构工程]