薄膜结构气弹动力稳定性研究

将扁壳的无矩理论和流体的理想势流理论结合起来对薄膜结构的气弹动力稳定性进行了研究,提出了结构失稳的判别准则,确定了结构失稳临界风速。首先应用扁壳的无矩理论建立了薄膜结构的动力平衡方程。然后假设来流为均匀的理想势流,考虑流固耦合作用,对风向沿结构拱向和垂向时分别采用不同的气弹模型确定了作用于薄膜表面的气动力,得到了两种情况下薄膜结构的气弹动力耦合作用方程。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,得到了一些重要结论,并提出了防止薄膜结构气弹失稳的一些基本措施。

ON AERODYNAMIC STABILITY OF MEMBRANE STRUCTURES

The aerodynamic critical instability wind studied by combining the non-moment theory of thin velocity of three-dimensional membrane structures is shallow shells and the potential flow theory in fluid mechanics. The dynamic equilibrium equation of the structure is established using the non-moment theory of thin shells. It is assumed that the coming flow is ideal uniform potential flow. The aerodynamic interaction equations of the membrane structure are obtained for the wind in the arch or sag direction of the structure based on the aerodynamic force determined using potential flow theory and thin airfoils theory. The wind-structure interaction is taken into account in the equations. 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 critical instability wind velocity. Finally, some important conclusions are obtained from parametric analysis.