Buckling of wind loaded cylindrical shells

Cylindrical shells subject to buckling due to wind loads in engineering practice generally are thin walled storage tanks, either with closed top or with a floating roof. In the design procedure of such tanks the stability analysis is an additional check only. For that purpose the buckling analysis should be reduced to a calculation not too theoretical or time-consuming, since in addition stabilizing measures by means of stiffening rings will be rather inexpensive. This paper presents a design concept for the buckling analysis of windloaded tanks, based on results of wind tunnel-tests. Included in this concept is further on the interaction of wind loads with internal vacuum or internal pressure as well as additional axial forces, since such loading conditions may occur frequently in practice. Although the test data refer to models of constant wall-thickness the design concept could be extended to tanks with varying wallthickness. More over some information is given about the required stiffness of secondary rings based on theoretical investigations. These result in quite small sizes of stiffening rings compared to those proposed in some design Codes. (orig.)