Abstract
The floating roofs are used in aboveground oil storage tanks to prevent evaporation of the content. The single-deck floating roof consists of a thin circular plate called a deck attached to a buoyant ring of box-shaped cross section called a pontoon. In large diameter tanks, a center pontoon may be attached on the center of deck plate of the single-deck floating roof. The center pontoon is a small cylinder with cone roof, and is considered to reduce the risk of pontoon buckling under the accumulated rain water condition. This paper describes the deformation analysis of the single-deck floating roofs with center pontoon under the accumulated rain water condition using the axisymmetric shell finite element method. The load incremental method, in which the equivalent nodal forces due to the rain water converges to identify to the rain water load derived from the deflected deck shape, is used.
