仿生PDC齿旋转破岩时的温度场和破岩特性模拟研究

Simulation Study on Temperature Field and Rock Breaking Characteristics of the Bionic PDC Cutter in Rotating State

  • 摘要: 针对常规PDC钻头破岩效率低、钻头泥包和使用寿命短等问题,以穿山甲鳞片、蝼蛄爪趾、鲨鱼牙齿和扇贝壳作为仿生原型,从多个维度进行结构仿生,设计了一种新型耦合仿生PDC齿。采用有限元法、弹塑性力学等方法,建立了仿生PDC齿的破岩仿真模型,利用有限元软件ABAQUS的温度–位移耦合显式侵彻接触算法和显式动力学模块,研究了仿生PDC齿破岩过程中温度场的变化规律和破岩方式,并与常规PDC齿进行了模拟对比。模拟结果发现:仿生PDC齿与常规PDC齿在破岩时的温度传递过程存在较大差异;仿生PDC齿能够防止钻头泥包的产生,且能够减少摩擦热的集聚,避免高温热失效,延长其使用寿命;仿生PDC齿破岩速度更快,对岩石的破碎更加彻底。研究表明,仿生PDC钻头的现场适用性较好,具有较好的现场推广应用价值。

     

    Abstract: Some drawbacks exist in conventional polycrystalline diamond compact (PDC) bits such as low rock breaking efficiency, bit balling, and short service life. To solve these problems, a new coupling bionic PDC cutter was designed by taking the scales of pangolins, claw toes of mole crickets, shark teeth, and scallop shells as bionic prototypes to construct bionic structures in multi-dimensions. Finite element and elastoplastic mechanics were employed to build rock breaking simulation model of bionic PDC cutters. The finite element software ABAQUS was used to study the variation law of the temperature field and rock breaking modes of bionic PDC cutters during rock breaking by temperature-displacement coupled explicit penetration contact algorithm and explicit dynamics module. The comparative simulation shows that bionic PDC cutters differed greatly with the conventional PDC cutters in the temperature transfer process during rock breaking. Bionic PDC cutters could prevent bit balling, reduce the accumulation of friction heat, avoid high-temperature thermal failure, and prolong the service life. Moreover, Bionic PDC cutters featured fast speed and thorough rock breaking. The research verifies that bionic PDC bits have good practicability and show great values in promotion and application in the field.

     

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