Analysis for VIV induced fatigue damage of a marine riser with 2-DOF

By introducing Pseudo-excitation method of the random vibration theory into VIV calculation of a marine riser,a numerical calculation method was established.The analysis of in-line and flow-cross 2-DOF random vibration responses of the marine riser was performed via the programming codes based on this method.Comparing the calculation results of the flow-cross response of the riser with the terst ones,the feasibility of application of Pseudo-excitation method in VIV calculation of the marine riser was verified.The computing time was recorded to validate the higher calculation efficiency of this new method.The fatigue damage rate of the riser per year was evaluated and the service life of the riser was predicted based on the P-M criterion.The study results provided a reference for calculation of VIV response and engineering design of a marine riser.