月球钻取采样钻头结构参数对力学性能的影响

基于对螺旋钻头的输出月壤阻力、驱动力矩及月壤失效区的分析，建立了钻头的力学模型，该模型综合考虑切削具内外侧面与月壤之间的压力及摩擦力，考虑月壤侧向失效面的面载荷对钻头切削具周向力矩、总功耗及月壤失效距离的影响，数值仿真与试验结果校验了模型的正确性。在数值仿真过程中采用深层月壤本构关系的Mohr-Coulomb模型,使仿真更加符合月壤内摩擦角大于22°的真实情况。利用该模型分析并获得了钻头结构参数对切削具功耗和失效距离的影响规律，以钻头功耗最小为优化目标，用遗传算法对钻头结构参数进行了优化，优化结果降低了钻探过程中的烧钻风险。可为钻取式自动采样机构的钻头设计提供理论依据。

Effect of Structure Parameters of Drill Bit on Mechanical Performances of Lunar Automatic Drill Sampling Mechanism

Based on the analysis of resistance forces and driving torque of spiral drill bit and lunar failure field, mechanical models of drill bit are established , models which are not only considered with pressure and friction between the lateral surfaces of cutter and lunar soil, but also considered with the effect of the surface load of lateral failure surface on circumferential torque, total power consumption of drill bit and failure distance of lunar soil. The models are validated by simulation results and experiment results. Mohr-Coulomb model suitable for deep lunar soil is applied to simulation process, which is better consistent with the real situation that internal friction angle is greater than 22°. The rules of effect of drill bit structure parameters on power consumption and failure distance of cutter are obtained by models above. Minimal power consumption of drill bit is selected as an optimization object , and structure parameters of the drill bit are optimized by using genetic algorithm. Optimizations results reduce the risk of drilling failure. Present paper provids an approch for design of drill bit of automatic drill sampling mechanism.