The Space Configuration And Dynamic Behaviors Of Deep-sea Mining System Under The Dragging Mode

At present,the serious situation of shortage of land resources in the world,people have to the development and utilization of marine resources in ocean extremely urgent.Exploitation of seabed mineral resources needed the deep-sea mining system,which is the largest scale in the history of human engineering system,at the same time,because of the complicated marine environment,such as the seafloor geological condition,nonlinear wave,the unsteady current,seasonal and sudden marine disasters,the structure safety of the deep-sea mining system is needed to be studied under the complicated environment.Based on the theoretical analysis and numerical simulation as the main research methods,according to the working environment of deep-sea mining system,the space configurations and the dynamic behaviors of transmission line and the collector machine in deep-sea mining system under the dragging work mode is researched,and then the reference bases for the design of the deep-sea mining system is provided.The main research contents and conclusions are as follows:1.The multi-rigid-body discrete element of the scope of application and its basic ideas is described,the space beam element stiffness matrix and the global stiffness matrix basis on the theory of linear beam is deduced,and then,the discrete element model is established,which successfully applied to the transferring problem of the large deformation force between cables and the motion of rigid body.2.All kinds of marine environment loading and boundary conditions acting on the pipeline system and the collector system is analyzed,and then the simplified mechanical model of deep-sea mining system is established.Morison model is discussed in order to calculate the model accurately,and the Wake I model and Wake II models considering the effect of Wake,and the scope of application of the three kinds of fluid dynamic mechanical model is gave.3.The simulation model of the deep-sea mining system is established by virtual prototype technology,and the detailed programming is described clearly.4.The dynamic behaviors of the deep-sea mining system under dragging work mode is studied.Considering the dragging speed,fluid dynamic mechanical model,the length of pipeline and the mining ship heaving amplitude,which have important influence on dynamics behavior of the system,and a variety of different level indicators of above factors is designed,and then the simulations are finished by the virtual prototyping method.The results show that the more dragging speed and the more smaller frictional resistance of collector;the Wake I model calculation results relatively conservative for the others models;the more mining of the longer of the pipeline and the more unstable of the space configuration and the dynamic characteristics of the system;the more ship heave amplitude,and the more greater fluctuation amplitude,but cycle unchanged.