| Summary |
Wind loads on cylindrical free roofs have been studied in a wind tunnel. The main objective of the present study is to propose appropriate wind force coefficients for designing the main wind force resisting systems of the roof considering the dynamic load effect of turbulent winds. Because the rise-to-span ratio f/B is regarded as the most important parameter, five models with different f/B ratios ranging from 0.1 to 0.5 were tested. Overall aerodynamic force and moment coefficients were measured with a six-component force balance. Wind pressures on the top and bottom surfaces of the roof model along representative two lines (Lines C and E) were measured simultaneously for various wind directions. Wind pressure distribution on the whole roof was calculated by CFD (computational fluid dynamics). RANS (Reynolds averaged Navier-Stokes equations) model was used to calculate the time averaged wind pressure distributions. Assuming that the roof is rigid and supported by four corner columns, the axial forces induced in the columns supporting the roof are regarded as the most important load effect for discussing the design wind loads. Based on the results, wind force coefficients for designing the main wind force resisting systems are proposed. In practice, the roof is divided into three zones, i.e. windward, central and leeward zones, and constant wind force coefficients are provided to these zones. Two load cases, which correspond to the maximum tension and compression induced in the columns, were considered. Finally the results on the maximum and minimum peak wind force coefficients along Lines C and E are presented, which may present useful information for discussing the wind loads for the designing of cladding/components.
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