Type of Document Master's Thesis Author Vakkalanka, Suryanarayana Author's Email Address firstname.lastname@example.org URN etd-05192000-13390028 Title Simplified Bow Model for a Striking Ship in Collision Degree Master of Science Department Aerospace and Ocean Engineering Advisory Committee
Advisor Name Title Brown, Alan J. Committee Chair Hughes, Owen F. Committee Member Kapania, Rabesh K. Committee Member Keywords
Date of Defense 2000-03-01 Availability unrestricted AbstractThe serious consequences of ship collisions necessitate the development of regulations and requirements for the subdivision and structural design of ships to reduce damage and environmental pollution, and improve safety.
Differences in striking ship bow stiffness, draft, bow height and shape have an important influence on the allocation of absorbed energy between striking and struck ships. The energy absorbed by the striking ship may be significant. The assumption of a “rigid” striking bow may no longer hold good and typical simplifying assumptions may not be sufficient.
The bow collision process is simulated by developing a striking ship bow model that uses Pedersen's super-element approach and the explicit non-linear FE code LS-DYNA. This model is applied to a series of collision scenarios. Results are compared with conventional FE model results, closed-form calculations, DAMAGE, DTU, ALPS/SCOL and SIMCOL. The results demonstrate that the universal assumption of a rigid striking ship bow is not valid. Bow deformation should be included in future versions of SIMCOL.
A simplified bow model is proposed which approximates the results predicted by the three collision models, closed-form, conventional and intersection elements, to a reasonable degree of accuracy. This simplified bow model can be used in further calculations and damage predictions. A single stiffness can be defined for all striking ships in collision, irrespective of size.
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