单齿回转切削力学模型的研究进展

Advances and trends in the study on rotary cutting mechanical model of single cutter

碎岩机理研究是提升碎岩效率和提高钻头寿命的前提和依据,而回转切削力学模型是碎岩机理的重要研究基础。通过对国内外典型单齿回转切削力学模型调研分析,归纳出力学模型研究动态主要表现在基于岩石不同破碎形式及岩石与切削齿不同接触形式方面。岩石切削力的分解由初期的切向力和轴向力,发展为主切削力、摩擦力以及切削齿磨钝后力的分解,认为切削力的分解及传递过程直接影响切削齿对岩石作用的应力分布状态,从而导致岩石破碎形式的差异。这些差异主要体现在岩石宏观和微观2种不同破碎形式:岩石的宏观破碎形式主要是由拉伸作用或者剪切作用导致破碎;岩石的微观破碎形式表现为拉剪联合作用导致破碎。微观破碎以内部裂隙产生到裂纹扩展,最终导致岩石宏观破碎现象。最后对单齿回转切削力学模型研究的发展方向提出一定建议。

The study of rock fragmentation mechanism is the premise and foundation for improving the efficiency of rock breaking and improving the life of bit.The rotary cutting mechanical model is an important research basis for rock cutting mechanism.By investigating the mechanical models of typical single-tooth rotary cutting in the world,it’s concluded that the research dynamics of mechanical model is mainly reflected in the different types of rock fractures and the different contact forms between rock and single cutter.The decomposition of cutting force develops from the initial tangential force and axial force to the main cutting forces,friction forces and the blunt force of the cutter.It’s believed that the decomposition and transfer process of cutting force directly affects the stress distribution state of rock,which leads to the difference of rock breaking forms.These differences are mainly reflected in the rock macroscopic and microscopic forms of rock breaking.The macro-crushing of rock is mainly caused by the action of stretching or shearing,and its micro-crushing of the rock is manifested by the combined action of tensile-shear breakage and damage.The micro-crushing is caused by internal crevices to crack propagation,which eventually leads to the macro-crushing of rock.Finally,some suggestions on the development trend regarding the rotary cutting mechanical model of single cutter were presented.