Wind loads on a steel greenhouse with a wing-like cross section

Abstract

The authors have proposed a new type of greenhouse with a cross section similar to a wing. Such a cross section reduces the wind loads and realizes a long-span structure. Simultaneous pressure measurements were made with a scale model in a simulated turbulent boundary layer. First, the effects of wind speed and surface roughness of the model on the pressure distribution were investigated; several kinds of commercial sand paper were used for roughening the surface. Then, the design wind load for the main force resisting systems is discussed, based on three kinds of evaluation methods, i.e. a time-history response analysis, the LRC method and a gust effect factor approach. The results indicate that the gust effect factor approach gives a reasonable result for winds roughly normal to the ridgeline, while it results in a wind load distribution different from those predicted by the other two methods for oblique winds. The LRC method generally gives a result similar to that of the time-history response analysis. However, the result depends on the load effect under consideration. The value of peak factor is also dependent on the load effect; it is generally larger than 3.5. Finally, the peak pressure coefficients for cladding design are briefly discussed.