恒扭矩工具组合式非标碟簧试验与数值分析

恒扭矩工具是一种运用在石油钻井领域的高效破岩工具,影响该类工具性能的关键因素是非标组合式碟簧的力学性能。采用Almen-Laszlo(A-L)法与有限元法(finite element method, FEM)对组合式碟簧按不同叠合片数、摩擦状态进行静力分析,得到载荷-变形曲线、等效加载/卸载刚度、功损比、极限载荷变化曲线;对组合式碟簧进行动态响应分析,得到在不同加载速率、预压量、载荷幅值、加载频率下的力学性能。结果表明:考虑大变形与塑性变形的有限元结果与试验结果吻合度更高,A-L法产生偏差与实际等效摩擦因数不在设定的标准区间内有关;考虑系统稳定性与阻尼耗能,优选出碟簧组的组合形式为4片叠合,最小对合单元预压量取3 mm,对合组数20组。研究结果对该类工具的研发具有科学的指导意义。

Experimental and Numerical Study on combined non-standard disc spring in constant torque tool

: The constant torque tool is an efficient rock-breaking tool used in the field of oil drilling and non-standard combined disc springs are the key factor affecting the performance of such tools. The load-deformation curve, equivalent loading/unloading stiffness, power loss ratio and ultimate load variation curve were obtained by using the A-L method and finite element method conducted on combined disc springs with different stacking numbers in series and friction state. However, dynamic response analysis was performed to consider the mechanical properties under different loading rates, preload, load amplitudes, and loading frequencies. The results show that the finite element results considering large deformation and plastic deformation are more consistent with the experimental results. The deviation of A-L method is related to the fact that the actual equivalent friction coefficient is not within the set standard range; Considering the system stability and damping energy consumption, a combination form of 4 stacking in series is preferred, the preload of a minimum unit is 3mm, and the number of stacking in parallel is 20 groups. The research results have scientific guiding significance for the development of such tools.