Investigation On Fluid-structure Interaction Of One-way Tensioned Membrane Structure Using Dynamic Boundary

Membrane structure is a new kind of long-span structure, which is developed in the mid-twentieth century and widely used in recent years. It’s characterized by lightweight, stiffness, small-damping, so wind load is the decisive load during the structural design. Membrane structures are prone to produce large deformation and vibration under wind load, which may affect the flow around structure and wind pressure distribution in turn. It’s necessary to pay special attention to FSI in wind-resistant of membrane structures. The research of FSI on membrane structures still has a long way to go because of its extreme complexity. There are three main methods to solve the problem: the analytical method, CFD numerical simulation methods and the aero-elastic model wind tunnel tests. So far, the numerical simulation combined with aero-elastic model test is an efficient way to study FSI of membrane structures.Based on dynamic meshes of the numerical simulation platform FLUENT, the problem of FSI on one-way tensioned membrane structure has been transformed to that of the moving boundary in this paper.Firstly, the moving boundary controlling method and dynamic mesh updating scheme were confirmed for the coupling flow filed of one-way membrane structure. Then, the flow phenomena of one-way tensioned membrane structure was reproduced based on dynamic meshes according to the condition of aero-elastic model test under 10m/s. And the displacement response of structure was also analyzed based on the wind pressure obtained by numerical simulation. The CFD could give results in accordance with the test, which shows that the numerical simulation results could reflect the characteristics qualitative of FSI on one-way membrane structure.Based on dynamic meshes, the FSI of one-way membrane structure under specified simple harmonic motion forms was investigated by considering the effects of vibration factors, such as equilibrium position of membrane structure, vibration amplitude, vibration frequency and vibration waveform,. The results showed that vortex would be more obvious with the increase of equilibrium position, which plays an important role on flow filed form. And with the increase of vibration amplitude, vibration frequency and vibration waveform, the dissipative effect of vibration on the flow field would be more obvious, and the flow filed form would tend to be stable. Besides, the flow field frequency would be controlled by vibration frequency of structure.Lastly, in order to study the FSI of one-way tensioned membrane structure under random vibration, the flow filed was simulated at different wind speeds, where the vibration response of membrane structure was determined according to the aero-elastic model tests. The results showed that structural vibration would be more notable when the wind speed exceeds a certain post, and the average wind pressure would be weakened to some extent, and the form of fluctuating wind pressure distribution would be changed when compared with that at low wind speed.