Static wind loads on rigid roof model with complex hyperbolic geometry

Abstract

The use of tensioned structures, such as membranes, as solutions for roofing and other kinds of covers has become more and more frequent. Current regulations do not provide detailed information about the coefficients needed to develop efficient designs, regarding wind loads. A lot of simulations and tests have been performed on different geometries which are typically used in these kinds of designs. However, no precise and clear standard has been established, yet, in order to regulate efficiently this application. Current regulations consider only simple geometries, while the effects of the interference between multiple covers or between a cover and the near urban environment is completely absent. In this paper are presented the results obtained from testing a 1:75 scale complex geometry model in a boundary layer wind tunnel. More precisely a model of a parking lot for vans, roofed with a complex geometry tensioned membrane was tested in order to measure its pressure distribution. Due to the high complexity of the geometry and in order to obtain a better description of the effects of the wind it was decided to lead wind tunnel tests to validate and to verify the load conditions over the roof. Information about wind load distributions for simple geometries such as cones, hyperboloids, etc. alone can be easily found in current technical bibliography. However, when designs are based on more complex shapes, including arrays of simpler shapes, a profound lack of information is observed. Therefore, it is not possible to calculate the wind loads over the membrane which are needed to dimension the supporting structure.