Experimental Study of Wind Pressure on a Long-Span Canopy Roof Structure Using a Wind Tunnel

Abstract

The wind pressure characteristics of the surface of a long-span canopy roof structure were investigated in detail using synchronized pressure measurement tests on a rigid model in an atmospheric boundary layer wind tunnel. The mean and fluctuating wind pressure distribution characteristics, power spectral density and coherence of the fluctuating wind pressure between different measurement points were analyzed. The results showed that the wind direction had a significant impact on the wind load distribution across the surface of the long-span canopy roof structure. When the short axis of the roof structure faced the wind, a positive pressure area was formed under the impact of the incoming flow, with the resulting turbulence being the main cause of excitation. When the long axis of the roof structure faced the wind (wind directions of 0° and 180°), a columnar vortex was formed on the windward side of the front edge of the roof structure and a suction force was created at the separation points, with the main excitation of the wind load being intermittent vortex shedding. The resulting spectral content was complex. The coherence of the measurement points on the roof structure surface decreased continuously as the distance between them increased. The correlation between the same two measurement points obviously also differed according to the wind direction. However, the coherence between measurement points aligned to the wind direction was stronger than it was in a cross-wind direction.