爬行器驱动轮正压过程分析

Analysis of the normal indentation process caused by tractor wheels

轮式水平井爬行器依靠驱动轮与管壁的接触产生牵引力。目前已有的相关研究均忽略了接触导致的管壁塑性变形压痕,简单地利用摩擦因数的经验值来处理力的关系,导致结果误差较大。该文针对压痕形成过程利用滑移线理论,在楔形压头压痕模型的基础上,建立了正压力和转矩同时作用下的正压(轮齿对称轴线垂直于管壁)压痕计算模型。有限元仿真反映了在不同受力条件下塑性变形区域的变化规律,也验证了主动力与压痕形状的定量关系。压痕测量试验证明了理论模型用于计算驱动轮压入深度和压痕隆起高度的正确性,为今后的驱动轮斜压建模、牵引力建模等研究奠定了基础。

The traction force of wheeled horizontal-well tractors is mainly produced by the contact between the wheels and the pipe walls.Previous studies ignored the plastic deformation caused by the contact between the wheels and the walls and used empirical friction coefficients to model the forces,which has led to significant errors.This paper derives a wedge indentation model(the wedge symmetry axis is perpendicular to the pipe wall)based on the simultaneous action of the normal force and the torque to predict the indentation formation according to slip line theory.Finite element analysis results not only show the plastic deformation for various forces,but also verify the quantitative relationship between the forces and the indentation shape.Comparisons with measured indentation shapes shows that the theoretical model can predict the indentation depth and the pile-up height,which can be used to improve sideling indentation modeling of wheels for better traction modeling.