Analysis of Single-Point Mooring Submerged Buoy System Excited by Flow in Shallow Sea

In order to analyze the vibration response of single-point mooring submerged buoy system with fiber cable in different flow velocity condition, the drag force and lift force are calculated based on the flow velocity gradient model. And then the dynamic model of submerged buoy is established by lumped mass method. The vibration responses under different flow excitations are analyzed in time and frequency domain. It's shown that the tension value is 3000N and the frequency is 0.22Hz in the connection point between cable and buoy, meanwhile the peak vibration in 0.46Hz is caused by the nonlinear material property of the fiber cable. Besides, the frequency of vertical vibration is half of the horizontal vibration and the amplitude is the twice, which means that the lift force has more obvious effect on the buoy vibration.