In this paper, a passive damper based on energy dissipation through shock and dry friction (shock-friction damper) is investigated regarding its design and effectiveness for damping self-excited torsional vibrations similar to those occurring in deep drilling. The results are compared to the results of conventional friction dampers. The effectiveness of the damper for different operational drilling parameters that change during the drilling process, such as the weight on the bit and the rotary speed of the bit, is analyzed. Two linear reduced order models of a drill string that are based on a complex finite element model are set up. One is reduced using the component mode synthesis and one is reduced to the identified critical mode. A lumped mass represents the inertia of a forcedly connected nonlinear damper. A combined reduced order model of the complex system and the inertia damper is introduced to investigate its dynamic motion and stability. Particular focus is on the energy flow within the dynamic system and on the change of the dissipation energy in the contact. A semi-analytical solution is derived using the harmonic balance method that is used to investigate the damping effect for various designs and operational parameters. Herein, the modal properties as well as parameters of the damper are examined regarding the damping effect and the stability of the system. Finally, the capability of the mechanism to suppress the self-excitation due to the bit–rock interaction in a drilling system is discussed, and recommendations are made with respect to the design parameters and placement of the damper.

中文翻译：

---

基于冲击和干摩擦耗能抑制钻井系统临界自激振动的非线性阻尼器的设计与研究

在本文中，基于通过冲击和干摩擦耗散能量的被动阻尼器（冲击摩擦阻尼器）研究了其设计和阻尼类似于深钻中发生的自激扭转振动的效果。将结果与传统摩擦阻尼器的结果进行比较。分析了阻尼器对钻井过程中不同操作钻井参数（如钻头重量和钻头转速）的有效性。建立了两个基于复杂有限元模型的钻柱线性降阶模型。一种是使用分量模式合成来减少的，一种是减少到识别出的临界模式。集中质量表示强制连接的非线性阻尼器的惯性。引入复杂系统和惯性阻尼器的组合降阶模型来研究其动态运动和稳定性。特别关注动态系统内的能量流动和接触中耗散能量的变化。使用谐波平衡方法推导出半解析解，该方法用于研究各种设计和操作参数的阻尼效应。在此，研究了阻尼器的模态特性和参数，涉及阻尼效应和系统的稳定性。最后，讨论了该机制抑制钻井系统中钻头-岩石相互作用引起的自激的能力，并就阻尼器的设计参数和位置提出了建议。