2020 年 5 巻 p. 44-50
The present paper discusses the wind-induced vibration of a long-span flat roof based on a wind tunnel experiment and a fluid-structure interaction (FSI) simulation with the free-vibration technique. The experiment and simulation were carried out in a smooth uniform flow and a turbulent boundary layer to evaluate the effect of turbulence on the dynamic response. The variation of mean and standard deviation of the roof displacement with wind velocity was obtained. In the experiment, the similarity between the practical membrane structure at full scale and the model used in the wind tunnel experiment was not satisfied because of the limitation of experimental conditions, such as the model material. Subsequently, an FSI simulation that couples a computational fluid dynamics (CFD) analysis for fluid with a finite element method analysis for structure was carried out to examine the practical behavior of a long-span flat roof in strong winds. In addition, the modes and natural frequencies of vibration at each wind velocity are detected by using a proper orthogonal decomposition analysis. The results indicate that the aerodynamically unstable vibration does not occur under the condition proposed by Matsumoto (1983). It is found that the mean deformation is one of the most important factors for assessing the vibration mechanism of long-span flat roofs.
