大跨度柔性屋盖结构的风荷载及风振响应研究

To obtain large space of building with no columns and to satisfy the functions, a number of long-span flexible roof structures are widely applied into the public constructions, for example, gymnasiums, hangars, theaters and so on. The wind load has recently become a major concern in wind-resistant design of modern large roof structures (such as spatial lattice, tensile membrane structures, charge membrane structures, tensile catenaries) due to their characteristics: light, flexible, lightly damped, low natural frequency etc. These buildings are usually taken as symbols and sights of a city, and so the influence of any demolishment of these buildings will be significant and terrible. So studies on wind load and wind response of long-span flexible roofs have a very important value..When wind flows around roofs, the airflow creates complicated pneumatic separation, reattachment, vortex and convection. On the same time it forms a high suction zone and produce dynamic load, and then the flexible roofs will suffer from wind-induced buffeting response. In this study, wind tunnel tests and theoretical analysis on flexible roofs various structure parameters are carried out. The coupling of the airflow and large deformation of membrane roofs are considered. The method to design perfect aeroelastic model for measuring vertical vibration of flexible roofs is established. The distribution of wind pressure for various roof shapes, wind response and wind load factor are also obtained. The results can be applied to wind-resistant design for long-span flexible roof and the compilation of concerned design code. The disadvantages of the application of quasi-steady theory into wind load on roofs are described. For flexible roof structures with medium deformation or with large deformation, it is found that the results obtained by time domain method well agree with those from the aeroelastic model wind tunnel tests. Furthermore, the method to predicted added air mass of close or opening flexible membrane structures is proposed..

研究大跨度柔性屋盖结构的风荷载及垂直向风振对工程建设和结构风工程研究领域的发展都具有极其重要意义。本课题建立并完善竖向风振的气动弹性模型试验方法和计算机数值分析方法，研究张拉式屋盖的大变形与风的相互作用、非大变形屋盖在多种结构参数条件下风荷载和放振响应，明确风振机理，确定风振系数及其计算方法，为规范的补充提供依据。