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    Side structure filled with multicellular glass hollow spheres in a quasi-static collision test
    (CRC Press, 2013)
    Schöttelndreyer, Martin
    ;
    Martens, Ingo
    ;
    Fricke, Wolfgang 
    ;
    Lehmann, Eike
    The evolution of ship constructions has been developed for hundreds of years and still exists in form of a conventional architecture consisting of frames, longitudinal and transverse girders, stiffeners, stringers and plates. The present numerical methods offer engineers the possibility of weight optimisation as well as the development of highly complex structures. But even with the use of the Finite Element Method itwas not possible to achieve a novel ship structure worldwide which is significantly different from conventional architectures. In the context of two collaborative research projects, the authors are carrying out several quasi-static collision experiments with different kinds of bulbous bow and double hull side structures on the test facility of the Institute for Ship Structural Design and Analysis ofTUHH. Following up the publication at ICCGS 2010, the current state of research will be presented. This paper focuses on ship side structures which are investigated by simulations and validated by experiments. Based on a conventional ship side structure and a rigid bulbous bow, enhanced side structures regarding the collision safety will be presented and afterwards compared with a conventional side structure. The aim of this work is to improve the passive collision safety without breaching present regulations of the classification societies. Therefore one conventional side structure is filled with granulate material and it is investigated by experiments and simulations. © 2013 Taylor & Francis Group.
    Publicationtype: Conference Paper
      62
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    Calculation of a stranding scenario
    (CRC Press, 2013)
    Zipfel, Bernadette
    ;
    Lehmann, Eike
    One soft grounding scenario - called stranding - is calculated with the FE method.A cargo hold section is modelled with shell elements and the rest of the ship is simulated with beam elements. The ground follows the Mohr-Coulomb material model. The results are compared to a calculation with a rigid ground. The vessel strands within the parallel midship and is subjected to the tide. Due to the water level reduction to half draft the hydrostatic forces significantly change. The correct hydrostatic forces as a function of water level and stranding position are applied. The ship structure collapses and elasto-plastic buckles are the predominant kind of damage. The soil characteristics influence the collapse mode. The damage is spread more globally if the ground is of sand. Therefore it is necessary to model the soft ground. A verification of the calculation method is also presented. © 2013 Taylor & Francis Group.
    Publicationtype: Conference Paper
      72
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    Collision tests with rigid and deformable bulbous bows driven against double hull side structures
    (CRC Press, 2013)
    Martens, Ingo
    ;
    Schöttelndreyer, Martin
    ;
    Lehmann, Eike
    ;
    Fricke, Wolfgang 
    Evaluation of ship collision safety is commonly carried out with a striking ship assumed to be rigid. This approach is in line with classic safety assessments taking a worst case scenario into account. It is in addition to that justified because the majority of ship-ship collisions occur without significant damage at the striking vessel. Nevertheless considering stiffness of the striking vessel might have noticeable influence on absorbable collision energies. Safety level could be increased significantly when design of bulbous bows is carried out also under the aspect of good crushing behaviour regarding collision load. However up to now experimental verification of this context is missing. This paper reports about collision experiments with rigid and deformable bulbous bows driven against double hull side structures that have been carried out on the test facility of the Institute for Ship Structural Design and Analysis of TUHH. Actual validation status of numerical calculations is presented based on test results also with regard to material behaviour. © 2013 Taylor & Francis Group.
    Publicationtype: Conference Paper
      144