Abstract:
Under the influence of marine environmental load, the vortex-induced vibration of the suspended submarine cable is easy to occur, which poses a threat to the service safety of the submarine cable. In order to study the vortex-induced vibration response of suspended span cable, a numerical software method is proposed to analyze the vortex-induced vibration of suspended span cable, and its accuracy is verified. Firstly, the calculation principle of numerical method is introduced. Then, the Orcaflex software was used to establish a numerical analysis model of the suspended span segment, and the accuracy of the calculation of natural vibration frequency was verified theoretically. By calculation, the maximum error between the theoretical calculation results of the first-order natural vibration frequency and the numerical results was 8.89%, and the maximum error between the theoretical calculation results of the second-order natural vibration frequency and the numerical results was 9.28%, which confirmed that the model was in good agreement. Then, the empirical formula method is used to verify the accuracy of the numerical model to calculate the vortex-induced vibration. The average error of the results is 9%, which verifies the accuracy of the model to calculate the vortex-induced vibration response of the suspended span segment. Finally, based on the Orcaflex software, the dynamic distribution characteristics and vibration characteristics of submarine cable suspension vortex-induced vibration are analyzed. The results show that the maximum tension and curvature of the cable appear at the separation point between the cable and the seabed under vortex-induced vibration. The maximum vibration amplitude is not directly related to the velocity, but to the mode of the suspended span. With the increase of the flow velocity, the vibration mode order in the cross flow direction of the suspended span cable increases. The research results of this paper provide an effective calculation model and method for the calculation and analysis of vortex-induced vibration of submarine cables, and the vibration characteristics of vortex-induced vibration can be further analyzed based on the calculation model.