Dynamic Analysis Of Sediment Sediment Bottom Sitting Process Of Deep Sea Lander

The geomorphology of the deep-sea environment is complex.There are seamounts based on hard rocks and seabeds based on rare soft sediments.When the benthic lander sits on the bottom of a hard seamount,the benthic lander is likely to cause deformation of the frame structure and damage to the equipment due to excessive impact stress on the bottom.Because the deep-sea surface sediments have the characteristics of high liquid limit,high plasticity,high porosity ratio,high water content,high consolidation coefficient,low compressive modulus and low shear strength.When the benthic lander sits on the bottom of the soft seabed,it is easy to cause the lander to sink too much in the sediment.Under such circumstances,the detection instruments and bottom-loading structures carried on the benthic lander are completely trapped in the sediments,causing the detection instruments to fail to accurately detect deep-sea environmental parameters.Due to the blockage of sediments,the ballast block cannot be separated from the body,and it is difficult to float,resulting in recovery failure.Therefore,the benthic lander is required to have good impact resistance and anti-sinking performance.In order to study and discuss the impact resistance and anti-sinking performance of the benthic lander,the following research has been made in this paper.First,The typical frame structure of benthic landers is analyzed when sitting on the bottom..Use the ANSYS Workbench static analysis module to analyze the relationship between the load and strain stress of the frame structure,and summarize the stress and deformation characteristics of the frame structure.Use the Explicit Dynamics module to analyze the relationship between the subsidence of the benthic lander on the sediment and the shape of the bottom of the frame,and summarize the anti-sag characteristics of the frame structure when sitting on the bottom.Second,taking the sediments in the Ocean C-C mining area as a reference object,and by consulting the existing relevant data,a simulated soil model and simulated soil mechanics parameters for deep-sea surface sediments are established.Based on the Bekker pressure model,Janosi and Hanamoto shear models,and the deep sea sediment shear damage evolution equation,according to the mechanical properties and parameters of deep sea surface sediment simulation,combined with the specificplacement scheme of the benthic lander and the corresponding bottom seat method on the sediment of the benthic lander.These deduce the bottom seat dynamics equation on the sediments.Third,the problem of the sinking depth of the benthic lander in the surface sediments at different bottom speeds is studied.The Explicit Dynamics module in ANSYS Workbench is used to simulate the benthic lander and seabed sediments.The dynamic responses of the benthic lander to the bottom collision with sediment at different speeds are analyzed.The equation of the relationship between bottom speed and settlement of the benthic lander prototype frame is established.Fourth,the test data of the prototype of the benthic lander delivered and recycled in the South China Sea are analyzed.This will provide a reference for the simulation and analysis of the design and application of the benthic lander.The research done in this paper provides a basis for the impact-resistant design and seat bottom velocity design of the benthic lander frame structure,and provides a simulation analysis method for calculating the bottom subsidence of the benthic lander.