For an economic development of a deepwater field, it is vital to estimate the fatigue life of the risers to ensure that they do not fail during their lifetime. Fatigue damage is normally incurred due to Vortex Induced Vibration (VIV) and due to random sea state waves and the associated platform motions. This paper presents the results of the fatigue analysis of a Steel Catenary Riser (SCR) connected to a floater in the Gulf of Mexico in 1000 m (3300 ft) water depth. The VIV analysis for the SCR was conducted using the propriety program Shear 7. The VIV results were obtained using mode shapes and curvatures generated by a Finite Element program. The Finite Difference approach was utilized to calculate the mode shape curvatures using the SCR static configuration at the floater mean position. In addition to the sagbend area, the results show that the fatigue damage due to VIV can be critical at the top joint area of the SCR as well when stress joint is used. The effect of using single mode analysis versus multi mode analysis is also investigated with low and normal shear current profiles.
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