Under the background of the rapid development of social economy,China is facing the development trend of double carbon target and new and old energy conversion,and the demand for some metal resources such as iron,manganese,zinc,nickel and chromium is increasing rapidly.Exploration data show that the deep seabed is rich in such polymetallic nodules.In order to solve the shortage of strategic metal resources in China,the state has formulated a strategic plan for the development of deep-sea mining.Deep-sea tracked mining vehicle is a widely recognized collection method.Whether it can run stably on deep-sea soft sediment directly affects the mining efficiency of seabed minerals.It is of great strategic significance to carry out relevant research to promote the commercial exploitation of deep-sea mineral resources in China.Based on this background,this paper uses theoretical analysis,laboratory test and numerical simulation methods to deeply study the interaction between the track and the soil during the collection operation of the deep-sea mining vehicle.The main work and conclusions are as follows :(1)Based on the theory of tracked soil interaction,the relationship between ground pressure and soil subsidence is briefly described.The ground pressure and distribution characteristics of the center of gravity offset of the mining vehicle are qualitatively analyzed.Combined with the shear relationship of the soil,the traction formula of the mining vehicle under uniform distribution and cosine distribution of ground pressure is derived,which lays a theoretical foundation for analyzing the influence of the traction force of the mining vehicle.(2)According to the in-situ mechanical parameters of soft sediment,the correctness and rationality of the microscopic parameters of the simulated soil particles are demonstrated by comparing the indoor test with the DEM simulated direct shear test.The soil bed is established to simulate the interaction of subsidence,shear and track soil,and the track model of interaction is constructed according to the structural parameters of ’ Kunlong 500 ’ ore collector.(3)According to the principle of Bekker test,the DEM simulation subsidence and shear test are carried out,and compared with the indoor test of similar working conditions.The results verify the reliability and rationality of the soil bed of the tracked soil interaction.The influence factors of the traction force of the track are analyzed by introducing the track and simulating the mechanical parameters of the soil.It is found that increasing the height of the track teeth can effectively improve the traction force of the track on the soft sediment.At the same time,reasonable control of the grounding pressure is conducive to the trafficability and drivability of the mining vehicle crawler on the soft soil.(4)Using Recurdyn and EDEM coupling to simulate the driving of the miner on the soft bottom soil,the influence of the track length-width ratio and the number of supporting wheels on the ground pressure and soil subsidence and the relationship between them are studied,and the effect of the track structure on the traction force is analyzed.The results show that the length-width ratio of the track and the number of supporting wheels have a certain effect on the ground pressure and soil subsidence,but the effect of the supporting wheels is limited by the number.The relationship between the mean ground pressure and the amount of soil subsidence when the mine car is stationary or moving is approximately consistent with the Bekker subsidence theory.In practical engineering,the net traction force of track can be improved by appropriately increasing the height of track teeth and adjusting the height-distance ratio.Reasonable design of track plate spacing and control of pitch height ratio can reduce the reverse resistance of the track,so as to improve the driving performance of the track on soft sediment. |