Modeling and Analysis of Rope Flexibility in Deep Sea Lifting Operations

With the development of exploiting marine resources into deep sea, the impact of lifting system, i.e. the rope and the attached payload, on the safe and efficient operation of deep sea applications is becoming more and more significant. In this paper, a continuous distributed parameter model of lifting system is presented. Then the analytical solution of the model regarding the motion and force transfer function, the dynamic and static force and the nature frequency by equivalent linearization is given. Furthermore, an example of deep-sea hoisting is enumerated to vividly description the analysis of the previous part. Also, time-domain simulations using MATLAB/Simulink combined with the Marine Systems Simulator are performed to analyze the displacement change of the load and crane tip and the stress on the rope. Finally, a model experiment is carried out to verify the previous conclusion.