| Now, deep-water exploitation has been the trend of the offshore engineering. The ocean riser, as the key equipment, has attracted more and more recognition. On the basis of 1500 meters long riser, this paper's research emphasizes the effect of VIV. Applying the frequency domain method, for top tension riser, dynamic behavior and fatigue damage have been calculated. Especially to the fatigue damage, the short term current and long term current are respectively calculated. The result show that the location of the largest fatigue damage is at the bottom of TTR. Besides, in the analysis of multi-modal response, the high mode response has more effect for TTR.It is further analysis of fatigue damage on VIV for deep-water top tension riser. With the top tension's increment, TTR fatigue damage rate is gradually decreasing. Flow field distribution in different circumstances, in uniform flow field, riser vortex-induced vibration fatigue damage rate was significantly less than the cases of Shear flow field. Besides, on the analysis of parameters, single-variable model for lift coefficient, the fatigue results of the analysis are somewhat conservative. Increasing reduced velocity double bandwidth, TTR greatest fatigue damage rate will increase accordingly. In addition, comparing different modal, the use of single-state analysis, with a rotating beam model constrained, the maximum fatigue damage rate with the top tension increases, but at both ends of the beam model hinged, the greatest fatigue damage rate with increasing top tension decrease.This paper also analysis the VIV suppression device, especially for the strake. The result shows that strake has benefit to decrease the VIV fatigue damage. Combined with the examples of structure, it also makes recommendations for the strake installation. The result can be achieved to reduce VIV of the purpose of fatigue damage and was able to meet the requirements of the fatigue life.
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