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Title: Collisions of Tension Leg Platforms with ships
Author: Balaji, Rajagpalan
ISNI:       0000 0001 3440 9275
Awarding Body: University of Southampton
Current Institution: University of Southampton
Date of Award: 1987
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In this thesis, collisions of Tension Leg Platforms (TLPs) with ships are investigated. Based on existing work on collisions between ships and offshore platforms, a mathematical model for the non-linear collison problem is formulated adopting a simplified approach. Kinematic relationships are obtained between the displacements of the colliding bodies. A system of springs located at the impact zone provides the mechanism for local absorption of energy through crushing of materials. Strain-rate effects on collision forces are ignored, and therefore only a static non-linear relation between collision force and deformation is considered. Load-indentation relations for ring-stiffened cylinders, normally comprising the main supporting cylindrical columns of TLPs, are developed utilizing a finite element software package (ANSYS). Hydrodynamic interaction between colliding bodies and the fluid in their vicinity are modelled through unit impulse response functions that provide the damping forces in terms of the histories of fluid motion and constant added masses that give rise to added inertia forces. Wave and current effects are excluded. Various collision scenarios involving a ship and a Tension Leg Platform are analysed using a computer program developed for the purpose. The program solves the integro-differential equations of motion for the colliding bodies in the time domain and produces results on the minematic parameters, collision forces, energies absorbed in local deformation and hydrodynamic forces. The post-collision response is investigated. This thesis attempts, therefore, to provide a rational and mathematically more rigorous numerical solution procedure for ship - Tension Leg Platform collisions.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: Ship-platform collision model