Finite element structural analysis of big yacht superstructures

The present financial crisis is imposing shipbuilders to reduce costs and construction times in order to prevent orders cutback. In yacht design studios, based on improved aesthetics, this goal cannot be accomplished by simply skimping internal and/or external furnishing, but it must be achieved by reducing weights and costs of structural components, without compromising the structural strength of the super yacht. In this scenario, superstructure scantling is becoming the most critical aspect of structural design as they are built by using materials, like aluminum light alloy, which have low mechanical characteristics. The actual trend of having very big openings on the hull sides, because traditional windows have been drastically enlarged to offer suggestive landscapes to the owners and their guests, further worsens the problem. Furthermore, the aforementioned cost and weight cutback is achieved by reducing beam scantling dimensions and plate thicknesses to the minimum imposed by the Classification Society Rules; this trend might became very dangerous if loads acting on the yacht are not thoroughly assessed during the preliminary design stage. In this paper, the structural response of aluminum light alloy superstructures is studied by a finite element approach, coupled with static and dynamic loads imposed by the Classification Society Rules, with particular attention related to the buckling phenomena that occurs to slender stiffeners around windows.