الفهرس 
Functions of Offshore PlatformsOnly 14 pages are availabe for public view
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Abstract
Oil and gas platforms are exposed to hazardous events, such as ship collisions. These collisions could lead to major structural problems and affect people’s lives, production continuity, and economic consequences. Offshore supply vessels (OSV) are the most common cause of ship-platform collisions.
Design standards establish guidelines that consider collision energy in the platform structure’s design calculations. The collision energy is 11 MJ for stern and bow collisions and 14 MJ for broadside collisions. It was calculated using a standard OSV with a displacement of 5,000 tons moving at a speed of 2 m/s. Recently, OSVs have been developed and increased in size. Therefore, the accidents recorded in recent years have higher collision energies.
The purpose of this thesis is to study and analyze a jack-up platform impacted by a standard OSV according to real existing data. The analysis is performed using the finite element analysis method with ABAQUS software. The ductility design principle is used. Thus, the ship is modeled as a rigid body. This approach allows the platform to dissipate the collision energy, and the ship is not allowed to deform.
The model has been developed for the tubular members of the platform (vertical chord member – horizontal member – diagonal bracing member) with different geometry and materials. The members have been studied using local and global analysis considering different collision scenarios. The platform’s boundary conditions and constraints have been idealized. The model has been validated with another model.
The results of displacement, impact force, and energy have been assessed and explained for each member. The jack-up platform did not collapse during the collision scenarios, but the members suffered considerable damage. However, modern ships are larger and may cause more significant damage or member dismantling. Safety specifications for the studied platform structure have been recommended.