Modeling and dynamic analysis of integral vertical transport system for deep-sea mining in three-dimensional space

This paper proposed a new three-dimensional numerical model of the integral vertical transport system (VTS) in deep-sea mining using the vector form intrinsic finite element (VFIFE) method. The method shows great advantages in solving complex dynamic behavior problems of VTS with large differences in mechanical properties and strong geometric nonlinearity. The governing equations are established according to Newton's second law and solved in the time domain by the central difference method. The simulation program for predicting the nonlinear dynamic behavior of VTS is developed with MATLAB and verified with the results of relevant literature. Then, a parameter sensitivity analysis is conducted to investigate the influences of the amplitude and period of the top vessel motion, current velocity, internal flow velocity and buffer mass on the VTS dynamic characteristics. The results show that the heave motions of the vessel are the most adverse motion state to the rigid pipe stress. The influence of the internal flow velocity on the system tension is significantly greater than the bending moment. The rigid pipe, which exhibits a higher sensitivity to each parameter than the flexible pipe, is the weakest area that needs more attention in the design.