开敞式索膜结构的气动失稳临界风速

考虑几何非线性的影响，利用无限薄的旋涡薄层模拟气流在结构表面形成的扰动，由非稳态Bernoulli方程和环量定理将空气压力表示成旋涡密度的函数；然后由涡格法结合耦合边界条件求出旋涡密度，根据系统的稳定性判据得到结构发散失稳临界风速的解析表达式．通过三维开敞式膜结构的计算分析，发现空间膜结构的曲率是影响结构气动失稳临界风速的主要因素．

Aerodynamic Unstable Critical Wind Velocity for Three-Dimensional Open Cable-Membrane Structures

The aerodynamic unstable critical wind velocity for three-dimensional open cable-membrane structures was investigated.The geometric nonlinearity was introduced into the dynamic equilibrium equations of structures.The disturbances on the structural surface caused by the air flow were simulated by a vortex layer with infinite thickness in the structures.The unsteady Bernoulli equation and the circulation theorem were applied in order to express the aerodynamic pressure as the function of the vortex density.Then,the vortex density was obtained by the vortex lattice method considering the coupling boundary condition.Through the numerical computation for the analytical expressions of the unstable critical wind velocities,some computational results and useful conclusions are obtained.It is found that the initial curvature of open cable-membrane structures has the evident influence on the critical wind velocities of the structures.