Single-Parameter Catenary Theory And Its Application In Marine Mine Pipeline Configuration Design

The current deep-sea mining system is mainly composed of three parts:the mining ship(water platform),power lifting system(pipeline)and power collection system(crawler type collector).During the deep-sea mining process,it should make the pipeline in proper spatial configuration and ensure the pipeline meet the strength requirements.This paper took the deep-sea mining pipeline as the research object.The catenary theory was used to analyze the spatial configuration and tension changes of deep-sea mining pipelines under different float layout schemes.The optimal solution was given by comparing different float layout schemes.This work provided a theoretical basis for the design of pipelines in deep sea mining systemsThe research contents and conclusions are as follows:(1)The classical catenary equations are derived.Based on the two-parameter solution,arc length differential is introduced into the classical catenary.After the transformation in hyperbolic,the classical catenary turns into a one-parameter form.The one-parameter can express the curvature diameter and tension of the catenary succinctly.(2)Under the action of concentrated force and even load,this paper analyzes the stress state of the catenary.For different stress states of the catenary,this paper gives different nonlinear equations of the catenary.Under the action of vertical concentrating force and even load,the catenary is solved through the semi display method and Newton iterative method.And the Newton iteration method is used in all the other working conditions.By using C language,the software for calculating the spatial configuration and tension of flexible pipeline is designed.(3)Under the action of a vertical concentrating force,the nonlinear behavior of the high catenary is analyzed.The existence of the minimum of the horizontal tension and the symmetry of the catenary configuration are found by calculation.And then,the author obtain the conditions of the extreme value of the horizontal tension and the symmetry conditions of the configuration by theoretical deduction.In order to prove the correctness of the theoretical calculation,a verification test is designed with stainless steel ring chain,and the test results show that the theoretical calculation is correct.(4)Based on the pipeline shape,the horizontal resistance of the collector,the number of floating bodies and the range of the collector,the design of the photoelectric composite cable is carried out.In the shallow sea,composite cables are designed as single or double arch depending on the length of cables.In the 500 meter seabed,composite cables are designed as double arch.The optimal plan is obtained by comparing different plans of the floating body.