薄膜结构的气弹动力失稳临界风速

Aerodynamic Instable Critical Wind Velocity of Membrane Structure

笔者采用解析方法研究了三维薄膜结构的气弹失稳临界风速。首先应用薄壳的无矩理论建立了薄膜结构的动力平衡方程 ;随后假设来流为均匀的理想势流 ,考虑流固耦合作用 ,采用不考虑流动分离和考虑流动分离两种气弹模型应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 ,确定了作用于薄膜表面的气动力 ,得到了两种模型情况下薄膜结构的气弹动力耦合作用方程 ;进而利用Bubnov Galerkin方法将此耦合作用方程转化为一常系数二阶微分方程 ,并根据Routh Hurwitz稳定性准则确定了薄膜的失稳临界风速 ;最后通过对临界风速的影响因素进行分析并对两种模型得到的结果进行比较 ,得到了一些重要结论。

The aerodynamic instable critical wind velocity of three-dimensional membrane structures is studied by analytical method. The dynamic equilibrium equation of structure is established by applying the non-moment theory of thin shells. Suppose the incoming flow is uniform ideal potential flow. The aerodynamic interaction equation of the membrane structure in either the flow separation is considered or not is obtained based on the aerodynamic force determined by applying the potential flow theory and the thin airfoils theory in which the wind-structure interaction is taken into account. Bubnov-Galerkin approximate method is applied to transform the interaction equation into a second order linear ordinary differential equation; and Routh-Hurwitz stability criterion is used to determine the instable critical wind velocity. Finally, some important conclusions are obtained from parametric analysis and comparison of these two cases.