Design And Simulation Analysis Of Seafloor Sediment Drilling And Sampling Mechanism Through Multi-barrel Connection

With the development of the human society,population expansion and energy shortage have brought serious problems to the sustainable development of human beings,so people have turned their attention to the ocean.The seabed drilling sampling robot plays an important role in seabed geotechnical exploration because of its flexibility and cheapness compared with large drilling vessels that drill directly from the sea surface and is important technical equipment that the world's marine powers are competing to develop.The drilling and coring mechanism system is the core skeleton of drilling robots and the core execution unit for geotechnical coring tasks.To meet the sampling and detection requirements,this thesis designs a set of drilling and sampling mechanism through multi-barrel connection.The specific contents are as follows:(1)The drilling and sampling mechanism through multi-barrel connection is proposed.Considering that the sampling depth of a single drill pipe is limited by its length,a multi-barrel sampling system is designed,which can greatly expand the drilling depth.At the same time,a drill pipe manipulating mechanism is designed,taking into account the automatic connection and storage requirements of drill pipes underwater.In addition,the wire rope double-range mechanism system was designed,taking into account the impact of the weight and size of the entire mechanism on the difficulty,reliability,and cost of drilling work.According to the functional requirements of drilling and coring,the system consists of three parts: a drive mechanism,a storage mechanism and a drill tool module.Multiple schemes were designed for each functional unit,and these were compared,analyzed,and optimized.(2)The motion and load characteristics of the mechanism are analyzed.According to the optimal mechanism configuration and design requirements,the overall structure and mechanism parameters of each function module are determined,and the Solid Works software is used to model each component unit in three dimensions.According to the established three-dimensional model and functional requirements,the motion transmission and load analysis of each functional realization mechanism are carried out.Each drive member is selected to meet the smooth and reliable operation requirements.(3)Finite element analysis is performed to obtain the mechanical characteristics during drilling and sampling.According to the established three-dimensional model by using the finite element method and importing the drill module file into ABAQUS,the seabed sediment model and the analysis model of the drill tool penetrating the seabed sediment are constructed.The stress,strain,and energy changes in the drilling process are simulated and analyzed by performing a series of operations such as assigning material properties,setting the analysis steps,and dividing the mesh.(4)The kinematics of drill tool operation is modeled and analyzed.According to the different functional characteristics and the action sequence requirements of each mechanism,using the coordinate transformation method,taking the process of the drill pipe leaving from to finally return to the sample storage mechanism as a complete motion cycle,the kinematics in the process of drilling and core movement is modeled and analyzed.It reveals the coordinated motion mechanism between the realizing mechanisms,forms a motion sequence,and provides a method of coordinated motion control for the realization of sampling work.