Equivalent static wind loads on saddle-shaped cable structures

An elaborate method is developed to analyze equivalent static wind loading (ESWL) of large span roofs, in order to cope with the problem of multi-mode vibration of these structures. The method includes two processes: the wind-induced response analysis and the static equivalent treatment. The wind-induced response and ESWL are both divided into the average, the background and the resonant components. In the process of wind-induced response analysis, background response is calculated with quasi-static method; resonant response is analyzed with the Ritz vector method incorporating the Proper Orthogonal Decomposition technique. In the process of static equivalent treatment, the background component of ESWL is obtained with the load-response-correlation method; the resonant component is expressed by several inertia loadings of dominating vibration modes. The developed method is employed to analyze wind-induced response and ESWL of a saddle-shaped cable structure. Distributions of ESWL are investigated with different wind directions and structural response types. The results show that the method is effective to study the wind-induced response and ESWL of large span roofs, by taking into account of multi-mode vibration of the structures.