ABSTRACT
The paper investigates the shear forces and bending moments on the braces and pontoons of a semi-submersible platform suitable for offshore applications under wave and wind loads. The responses of the platform which is composed of an array of floating vertical cylindrical bodies are calculated from the analytical solution of two boundary value problems, namely, the diffraction and the motion-radiation problems. They have been obtained through an analytical solution method using matched axisymmetric eigenfunction expansion formulations. In doing this, the hydrodynamic interactions among the cylindrical bodies that form the buoyant elements of the semi-submersible platform is of particular importance since the hydrodynamic characteristics of each cylindrical member in a multibody configuration may differ from the ones obtained for the same body considered as isolated due to hydrodynamic interaction phenomena. In that context, comparisons between the loads on the braces and pontoons with and without taking into consideration the interaction phenomena are presented.
