Simulation study for marine riser VIV displacement detection method based on IFFT

Vortex induced vibration (VIV) is the primary reason that accounts for the fatigue of deepwater riser systems. How to detect the displacement of riser caused by vortex induced vibration is the mainly issue in riser fatigue damage monitoring. The way that reconstructs the displacement by double integrating the acceleration signals will leads to unacceptable integration error. To the question, a new algorithm based on the Fast Fourier Transform pairs is presented. The cut-off ratio is defined. The impact that the factor such as lower cut-off frequency, sample length and signal to noise ratio effect the accuracy of the presented algorithm is studied. The simulation results show that this algorithm is effective.