基于刚体动力学-离散元耦合数值方法的复合地层盾构滚刀响应

随着盾构机制造技术的不断进步，隧道工程中使用盾构机的情况愈加普遍。滚刀作为一种优异的掘进刀具，在复合地层盾构机中普遍应用。滚刀在使用过程中处于动态滚动状态，离散多元化的岩土体将导致滚刀的动态状态呈现异常状态，从而导致滚刀和岩土体接触面间存在较大的相对滑动速率。在以往的离散元滚刀模拟中，研究者将滚刀设定为固定转速而未实现滚刀的动态滚动过程。本文使用刚体动力学（RBD）-离散元（DEM）耦合的数值模拟方法，实现了在数值模拟中的滚刀动态被动转动，进一步贴近工程实际。本文以强风化岩为破岩对象，模拟分析了不同贯入度、不同运动速度下的滚刀的动态运动过程。基于本文的初步研究分析发现：滚刀存在最优贯入度区间，低于该区间时滚刀不能进入动态转动状态，大于该区间时改善效果不明显且增大滚刀受力；滚刀启动时受到的扭矩先随滚刀运动而升高，到达某一峰值点附近后开始下降，随后在零值附近波动；滚刀启动峰值扭矩和运动速度正相关；滚刀达到峰值扭矩的时间和运动速度负相关。本文的研究手段可为相关研究者提供参考，本文的研究结果可为盾构刀盘刀具设计及盾构机的操作提供参考。

Study on the response of shield disc cutter in composite stratum based on RBD-DEM coupled numerical method

With the continuous progress of shield machine manufacturing technology, the use of shield machine in tunnel engineering is more and more popular. As an excellent tunneling tool, disc cutter is widely used in composite ground shield machine. The disc cutter is in a dynamic rolling state in the use process, and discrete and diversified rock-soil mass will lead to the abnormal dynamic state of the disc cutter, resulting in a large relative sliding rate between the contact surface of the disc cutter and the rock-soil mass. In the previous discrete element method simulation, researchers set the disc cutter as a fixed speed without realizing the dynamic rolling process of the disc cutter. In this paper, the numerical simulation method of rigid body dynamics (RBD) -discrete element (DEM) coupling is used to realize the dynamic passive rotation of the disc cutter in the numerical simulation, which is further close to the engineering practice. In this paper, the dynamic motion process of the disc cutter under different penetration and velocity is simulated and analyzed by taking the strongly weathered rock as the rock breaking object. Based on the preliminary research and analysis of this paper, it is found that there is an optimal penetration interval for the disc cutter. When the penetration is lower than the interval, the disc cutter cannot enter the dynamic rotation state. If the penetration is greater than the interval, the improvement effect is not obvious, and the force of the disc cutter will increase. When the disc cutter starts, the torque increases with the movement of the disc cutter and begins to decrease when it reaches a certain peak value, then fluctuates around zero; The starting peak torque of disc cutter is positively correlated with the movement speed; The time when the disc cutter reaches the peak torque is negatively correlated with the motion speed. The research methods of this paper can provide reference for relevant researchers. The research results of this paper can provide reference for the design of shield cutter and the operation of shield machine.