Buckling behavior of open-top, stocky flat bottom tanks subject to wind load

Flat bottom tanks are widely employed to store liquids, such as water, sludge and oil. In many cases, no roof is necessary to cover the tank or a oating roof is built. When these structures are exposed to wind a complex bearing behavior develops since the load pattern is nonlinearly distributed around the circumference. In recent years standard relevant research was mostly conducted on slender structures, such as chimneys and silos, which lead to first design recommendations. However, for stocky at bottom tanks, no design procedures are yet proposed. This paper aims at taking a closer look on at bottom tanks subject to wind load. Decisive parameters such as the radius-to-thickness ratio r/t, stiffness of the wind girder I, length-to-radius ratio l/r and the role of the imperfection amplitude are studied with a parametric finite element analysis. It is shown that the complex behavior imposes a challenge to prepare a design recommendation valid for a broad range of geometries, which allows economical results.