Study On Wind-induced Dynamic Response And Wind Tunnel Test Of Membrane Structures

From the second half of the last century, membrane structures have attracted great attention because of their novel shape and reasonable behavior. Many studies of membrane structures were focused on the form-finding, cutting patterns, static analyses and construction, rarely involved in the field of studying its characteristics of wind-induced vibration. From the view of structure analyses, great wind turbulence in the boundary layer makes such large-span flexible roofs as membrane structures generate powerful lift in the large section. Vortex and the convection are formed in the process of viscosity diffusion and fluid wake. The wind load including vortex-induced vibration is the main load to those kinds of structures. Studies on the characteristics of wind-induced and vortex-induced vibration to membrane structures have not only the value of academic research but also that of significant practical engineering.In the paper the characteristics of wind pressure of membrane structures is studied thoroughly with the help of wind tunnel model experiment. Added air mass on the membrane roof is analyzed in detail. Some meaningful results are obtained for mechanism of wind-induced and vortex-induced vibration of membrane structures by systematical studies about them.In the matter of wind tunnel experiments, the rigid and aeroelastic model for double-slop membrane structures with seal and opening on all sides, or opening a hole suddenly, are designed. The question that the tubes, connected to pressure taps, which measure the wind pressure on both upper and under surface of rigid models, do not influence wind field around building, especially under roof, is solved commendably. A series of analogy parameters such as Froude number are considered and used for aeroelastic model design. These analogy parameters between model and prototype are verified, and make possible that the results from model test in the wind tunnel can be applied to prototype directly.Wind-induced vibration is analyzed based on wind tunnel test and theoretical analysis. According to the data gained from the wind tunnel test in the different circumstance, the structures are analyzed by using finite element method in time domain. The comparative analyses prove that the results from the theoretical analysis have good agreement with those from wind tunnel experiment. It enunciates that this method turns out high reliability because load data are obtained from test directly, and avoids deviation from theoretical calculation based on the quasi-static assumption in the studies of wind-induced vibration of membrane structures.Based on the linear filter technology of random process, artificial wind speed processes are generated with the autogressive-type simulation methods, which consider time and spatial correlativity, and can be converted into time history record of fluctuating wind pressure. The formula to calculate additional air mass on the membrane in unsteady flows is performed and theoretical equation is provided. The vortex-induced vibration of membrane structures considered from the additional air mass is discussed and some important results are obtained.