Hydro-structural response simulations play an important role in decision-making


MARIN makes wide-scale use of various


hydrodynamic tools to calculate structural response. Report


highlights some recent applications.


H


ydrodynamic tools are used to calculate ship motions based on the wave loads over the hull and the mass distribution of the ship. The pressure distributions and inertia loads solved by the hydrodynamic tool can also be mapped on a structural model of the ship, which is generally a Finite Element (FE) model. By combining FE results with environmental and operational conditions, the local response at critical structural details can be assessed. This is mainly done for fatigue design calculations but can also be used for decision support.


Today, different hydrodynamic solvers are used at MARIN to perform hydro-structural calculations for ships and offshore structures. These are either 3D-panel or strip theory methods. The latest developments in some


of these solvers take a ship’s global flexibility into account in the calculation of the hydro- dynamic loads.


TULCS MARIN participated in the EP7 Framework Programme for the Ultra Large Container Ships (TULCS) project. One of the main research topics was focused on the hydro-elastic response of ships and the development of tools for simulations. Until now, ships were expected to be a rigid structure in waves, which means that deformations of the vessel’s structure under hydrodynamic loading were expected to be minimal. This is a reasonable approach for most ships but hull rigidity decreases as the vessel’s main dimensions increase. The limits of the rigid approach have been reached, particularly when considering the design of large container ships.


Stress distribution in a large containership in hogging (red coloured) and sagging (blue coloured) condition with respect to the mean still water load. In hogging condition, the top deck area of the structure will be loaded in tension. In sagging, the top deck area will be loaded under compression. The wave height distribution around the ship is the total wave height, including the incoming, diffracted, radiated wave and the static wave around the ship due to forward speed.


Marcus Schiere m.schiere@marin.nl 10 report


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