| At present,the extraterrestrial probe has confirmed the existence of water ice in the lunar polar region through remote sensing means such as radar,neutron spectrum and spectrum.Water can not only reveal the origin of life and the evolution of matter,but also be an important supply material for deep space exploration,which is related to the site selection and construction of future lunar scientific research base stations.The fourth phase of China’s Lunar Exploration Project plans to go to the lunar polar region for mining and exploring lunar soil water ice.It intends to use drilling method to collect the damage of lunar soil water ice by relying on the rotary cutting of drilling tools.However,so far,the detection information of lunar polar region is based on remote sensing means,and the relevant physical and mechanical properties of lunar soil water ice have not been obtained directly.Therefore,for the sampling and reconnaissance mission of lunar soil water ice in the permanently Shadowed region of the lunar South Pole,it is necessary to carry out cutting decoupling tests of surface icebearing simulated lunar soil to simulate the drilling and sampling conditions in the lunar polar region,so as to obtain the mechanical properties of ice-bearing simulated lunar soil under the cutting action of drilling tools,which can provide a basis for the design of drilling and sampling devices.In this paper,the physical and mechanical properties of lunar soil water ice in polar regions were analyzed based on the origin of lunar soil and the occurrence state of lunar soil water ice,and accelerated equivalent simulators highly similar to lunar soil water ice were prepared by comparing the known real lunar soil composition data with ground simulation materials.The simulation sample preparation process was optimized and improved according to the geotechnical test method standards.A complete process of preparing simulated samples of lunar soil water ice was designed,and the static parameters of the simulated samples were determined by variable Angle shear test and uniaxial compression test.Secondly,according to the physical environment of the lunar polar region and the drilling and sampling conditions of the lunar surface,a set of simulated cutting sampling load test platform in deep and low temperature environment was designed.Through decoupling method,the complex drilling and sampling method was simplified into single-edge linear cutting sampling.According to this method,the cutting load of simulated samples of lunar soil water ice was studied.According to the sampling conditions of the simulated samples,a set of simulated deep low temperature cooling equipment was designed,and the feasibility of cooling and temperature control of the low-temperature cutting test equipment under force load was verified by COMSOL platform and numerical simulation analysis method.Thirdly,Then,according to the practicability of drilling cutting sampling conditions,a cutting test scheme of simulated lunar soil with ice was developed.The influence of cutting parameters on cutting load was analyzed,and the influence of different variables on cutting load was tested.The cutting load characteristics of simulated soil water ice samples under different conditions were obtained.The cutting mechanism of simulated lunar soil with ice was given based on load curve and sample fragmentation in actual cutting operation,and the cause of load curve variation was explained.Finally,according to the mechanical strength characteristics of simulated lunar soil with ice under the condition of deep low temperature,the load model of simulated lunar soil with ice was studied and verified by using two typical cutting load models(Merchant shear failure model and Evans tensile failure model).A cutting model suitable for simulating lunar soil with ice in actual cutting conditions was obtained and its similarity was matched. |
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