深层月壤取心钻头构型设计及其力载特性研究

发布时间：2018-03-07 12:06

本文选题：阶梯型取心钻头　切入点：力载特性　出处：《哈尔滨工业大学》2013年硕士论文　论文类型：学位论文

【摘要】：我国月面钻取采样任务的主要目标是获取月表以下2m深且具有连续层理信息的月壤样品并返回地球，月球表面环境的复杂性和着陆器携带能量的有限性给采样任务的完成带来了很大的困难。针对月面采样过程中钻进力载不能过大，以防止着陆器发生倾覆的情况，本文在研究了国外地外星体采样技术和地面钻探技术的基础上，研制了一种具有阶梯形式的取心钻头。通过理论分析、仿真模拟和地面试验等手段，获得了取心钻头构型参数对钻进力载的影响规律。通过对月壤的物理性质和力学性质进行的研究，确定了主要性质参数的变化区间以及随深度的变化趋势，为取心钻头与月壤相互作用力学模型的建立提供了基础；对国内外模拟月壤的组成成分和制备方式进行了研究，制备了三类地面试验用模拟月壤，并建立了均质模拟月壤的本构模型，，为模拟取心钻头钻进均质模拟月壤的有限元仿真提供了基础，并为地面模拟试验的规划提供了指导。结合地质钻探中取心钻头的设计经验，提出了一种具有阶梯形式的取心钻头构型。基于取心钻头切削具作用土壤的失效机理和边界简化方式，建立了极限平衡状态下切削具切削月壤的力学模型，得出了取心钻头钻进月壤的钻压力与回转扭矩的解析模型，根据该模型研究了切削具切削角、底出刃高度和刃宽等构型参数对钻进力载的影响，并对取心钻头钻进月壤的初始钻进力载进行了预估。编写了基于Duncan-Chang模型的UMAT子程序，在有限元软件中建立了取心钻头与均质模拟月壤的相互作用力学模型，对钻进过程进行了仿真，得出了取心钻头钻进所需的钻压力和回转扭矩随钻进深度的变化情况；对切削具切削二维和三维月壤进行了模拟，验证了月壤的失效形式和边界简化假设的正确性；对取心钻头的阶梯形式和切削具镶焊方式、切削具刃宽和底出刃高度等构型参数对切削力的影响进行了仿真分析，得出了取心钻头采用阶梯形式能够比较好的降低钻进力载，而且获得了切削具镶焊方式、切削具刃宽和底出刃高度对切削力的影响规律。进行了针对均质模拟月壤和岩石的地面模拟钻进试验，采用单一构型参数变化而其他构型参数相同的对比钻头进行钻进试验对比分析，得出了取心钻头阶梯形式、阻隔环、切削具安装方式和钻头体锥角等取心钻头构型对钻进力载的影响规律。
[Abstract]:The main goal of the lunar surface sampling mission in China is to obtain samples of lunar soil with continuous stratigraphic information and return to Earth at a depth of 2m below the lunar table. The complexity of the lunar surface environment and the limitation of the energy carried by the lander bring great difficulties to the completion of the sampling task. In view of the fact that the drilling force load should not be too large during the lunar surface sampling process, in order to prevent the lander from overturning, On the basis of studying the sampling technology and ground drilling technology of foreign extraterrestrial stars, a kind of core-taking bit with ladder form is developed in this paper. By means of theoretical analysis, simulation and ground test, etc. The influence of core bit configuration parameters on drilling load is obtained. Through the study of the physical and mechanical properties of lunar soil, the variation range of main properties parameters and the variation trend with depth are determined, which provides the foundation for the establishment of mechanical model of the interaction between core bit and lunar soil. The composition and preparation method of simulated lunar soil at home and abroad were studied. Three kinds of simulated lunar soil were prepared and the constitutive model of homogeneous simulated lunar soil was established. It provides a foundation for the finite element simulation of simulated lunar soil by simulating drilling homogeneity of coring bit, and provides guidance for the planning of ground simulation test. Based on the design experience of coring bit in geological drilling, a kind of core bit configuration with ladder form is proposed. Based on the failure mechanism and boundary simplification method of cutting tool of coring bit, The mechanical model of cutting the lunar soil with cutting tool under the limit equilibrium state is established. The analytical model of drilling pressure and rotary torque of the core bit drilling the lunar soil is obtained, and the cutting angle of the cutting tool is studied according to the model. The influence of the bottom blade height and edge width on the drilling force load is discussed and the initial drilling force load of the core bit drilling on the lunar soil is estimated. The UMAT subprogram based on Duncan-Chang model is written, and the interaction mechanics model between core bit and homogeneous lunar soil is established in the finite element software, and the drilling process is simulated. The variation of drilling pressure and rotary torque with drilling depth is obtained, and the validity of the hypothesis of failure form and boundary simplification of lunar soil is verified by simulating the cutting tools in two and three dimensions. This paper simulates and analyzes the influence of the configuration parameters such as step form of core bit, insert welding mode of cutting tool, width of cutting tool edge and height of bottom edge on cutting force. The conclusion is drawn that the drilling force load can be better reduced by using step type of core bit. The influence of cutting tool width and bottom edge height on cutting force is obtained. In this paper, the ground simulation drilling test for homogeneous simulated lunar soil and rock is carried out. The contrast bit with single configuration parameter and the same other configuration parameter is used to carry out the contrast drilling test, and the step form of coring bit is obtained, and the barrier ring is obtained. The influence of the installation mode of cutting tool and the cone angle of drill bit on the drilling load.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P634.4;P184

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