Mohammad yourdkhani - M.Sc Student , Amirkabir University of Technology
Mehdi iranmanesh - Associate professor , Amirkabir University of Technology

Nowadays, with increase in needing for the source of energy, such as oil, using of the jacket structures become so important. These structures are subjected to failure because of fatigueresulted from the cyclic loading and stress concentration on the welded joints. By applying the internally ring-stiffener in the main members (chords), the effects of stress concentration on the structure's joints will be decrease, significantly. In this research work, a jacket platform was modeled by using ANSYS software with and without the ring-stiffener

Offshore platforms, Tubular joints, internally ring-stiffener, Finite elements