WIND TUNNEL TESTS ON AEROELASTIC EFFECT OF WIND-INDUCED VIBRATION OF TENSION STRUCTURES

Tension structures, such as cable net and textile structures, are characterized by their lightweight and flexibility, which make them rather sensitive to wind-induced dynamic excitation. In some cases, the interaction between structure and wind maybe play an important role to the wind induced response, which can not be accounted by conventional analytical methods. To solve this problem, a simplified aeroelastic model, based on theoretical analysis and wind tunnel test, was put forward firstly. Some important parameters, such as aerodynamic damping and added mass, were introduced to describe the additional aerodynamic feedback terms involved in this aeroelastic model. Then, a series of wind tunnel test of saddle-shaped membrane structures with rhombic plans were carried out to study the couple effects of wind and tension structures. Random decrement technique was adopted to identify these parameters. The variation of aerodynamic damping and added mass with wind speed, exposure, structural stiffness and vibration mode shape were analyzed especially, and the mechanics of wind-structure interaction were discussed. It can be observed from these researches that the wind-induced vibration of membrane structures are characterized by broadband and forced vibrations; the effect of aerodynamic damping is more significant than added mass, especially for lower vibration modes of structures, in which case the damping ratio can reach 15%; the magnitude of added mass is only about 1 time of structural mass; aeroelastic instability of entire structure have not occurred in all experiments, but in some cases local aeroelastic instability appeared in individual measurement points.