Transient Wind Loads on Circular Concave Cable Roofs

Experimentally-determined transient wind pressures on a rigid model of a circular concave roof are presented. The loadings are then used in an analytical investigation of the dynamic response of a cable network. Most of the energy of the turbulent pressure fluctuations appears to be concentrated at low frequencies and is somewhat dependent on the height to diameter ratio of the structure; however, no dominant periodicity in the pressure fluctuations is apparent. Correlation coefficients for pressures are approximately equal over the entire roof, indicating that the eddy size is fairly uniform throughout the separation bubble. Using a discrete element formulation, the lower natural frequencies of a concave cable network are found to be dependent only on the sag and diameter and are independent of the mass and stiffness of the system. The results of the dynamic statistical analysis indicate that the mean transverse displacements are relatively small compared with static values incurred under time-averaged pressures.