Research On Evaluation Of Lunar Soil Drilling-sampling Characteristics And Influence Factors

The paper is based on the third state of China lunar exploration,the corepurposes of the lunar soil deep-sampling is to obtain lunar soil samples of a certaindepth below the lunar surface,and maintain the bedding information which reflectedthe original geological features of lunar soil of the sampling locations.Meanwhilethe peak power of the lunar soil deep-sampling device was constrained.Regardingthe coring rate,sampling power and bedding information as the evaluationcriteria,the paper established an evaluation system for the lunar soil deep-samplingdevice by utility function aiming at building a guiding framework of multi-programcomprehensive screening.It analyzed some of the impact of factors,including thebedding information disturbances caused by the penetration of barrier-cut device,theestablishment of drilling process parameters and the impact on the cutting forcecaused by the bit.Finally carrying out tests against three options in order to verifythe theoretical model of the evaluation system.The scientific and rational evaluation system of lunar soil deep-samplingdevice was establised based on the comprehensive method of utility function.Theindex component of the coring rate,the sampling power and the bedding informationwas described in detail.The key to the comprehensive method of utility function wasthe single evaluation index value,the determination of the weight and the choice ofthe synthetic model.The process of a single evaluation index value,theestablishment of weight and the choice of the synthetic model were set down by thedimensionless method,analytic hierarchy process and arithmetic mean synthesisrespectively.Based on the strain field of half-space spherical cavity expansion,thetheoretical analysis of the bedding information disturbances caused by thepenetration of barrier-cut device was studied.It deduced the rational strain formulaof the deformation in the process of the penetration.Taking the rotation and feedspeed as independent variables,the sampling quality and power as the dependentvariables,the optimal drilling process parameters was acquired by numericalmethod.The function of the torque on the penetration per revolution was fit andshowed the detailed qualitative analysis of the experimental phenomenon.Itobtained the bit-lunal soil interaction model which showed the trends of cuttingforce in line with the rake angle,drilling tool-lunar soil friction angle,cuttingdepth,cutting edge width and lunar soil friction angle.Verified by experiments,the method of the second chapter applied to theoptions of the lunar soil deep-sampling device was feasible.