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Analysis of stress, strain and estimation of the fatigue life of amir kabir semi-submersible drilling platform by using hot spot method in Caspian Sea
Rahmatollah Ghajar
*Seyed Mohammad Navid Ghoreishi
Department of Mechanical Engineering, Mechanical Properties Lab, K.N. Toosi University of Technology, Tehran, Iran P.O.B. 19991-43344 Tehran, Iran, [email protected]
A RTICLE I NFORMATION A BSTRACT
Original Research Paper Received 13 May 2014 Accepted 16 July 2014 Available Online 26 October 2014
Offshore platforms are exposed to random cyclic loads imposed on the structure by natural phenomena including waves, sea currents, wind and etc, so fatigue analysis of these structures is one of the most important design steps. Hot spot method is one of the most common techniques for evaluation of the fatigue life of offshore platforms. In this approach, the stress adjacent to the weld is estimated by extrapolation from the stress distribution approaching the weld, as obtained by finite element method or perhaps from strain measurements on the surface. In order to calculate the fatigue life of Amir Kabir semi-submersible drilling platform, first model of platform is created. Then according to the environmental conditions of the Caspian sea, hydrodynamic forces exerted on the platform are calculated. The simulated hydrodynamic forces are then applied to the platform structure for calculating the stress and strain field in the whole structure. It is found that the intersection of column and pontoon is the critical section of the platform and hence the fatigue life of the structure is predicted in terms of conditions of this location.
Keywords:
Semi-Submersible Drilling Platform Hydrodynamic Loads
Fatigue Hot Spot Stress
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