Experimental investigation of wind effects on hyperbolic paraboloid roofs under synoptic wind and downburst flows

Membrane structures are widely employed in tensile architecture due to their scalability, geometric complexity, and strong architectural presence. Among common forms, the hyperbolic paraboloid (hypar) is distinguished by its geometric simplicity and structural efficiency, arising from its characteristic double curvature. This study introduces a comprehensive workflow for processing wind-load data on membrane structures and presents a detailed aerodynamic pressure-coefficient map for a hypar surface. Wind effects on a 1:25-scale hypar roof were investigated in a wind tunnel, with the flow permitted to pass beneath the membrane. The structure was tested under both synoptic ABL (Atmospheric Boundary Layer) and non-synoptic (downburst) wind conditions. Experimental net pressure coefficients were derived and are reported here. Additionally, top-surface and net pressure coefficients for synoptic winds are compared with results from previous studies. Based on the findings, a set of simplified pressure-coefficient maps is proposed to support practical design applications and potential future integration into design codes. The detailed pressure-coefficient dataset provided in this study offers a valuable resource not only for structural design but also for validating CFD simulations involving doubly curved membrane geometries.