摘要
考虑了切削力波动、质量偏心及切削液流体力对钻杆动特性的影响。在求解切削液动态流体力时,引入变分约束原理,在动力积分、迭代过程中实时形成修正的Reynolds方程变分形式的有限元方程及其扰动方程,同时求得了切削液流体力及其Jacobian矩阵,并且使其具有相互协调一致的精度。在求解钻杆系统非线性动力学响应时,通过改变系统的时间尺度,使系统周期轨迹的周期显式地出现在系统方程中,并将周期也作为一个参数参与到迭代过程中,减少了对周期轨迹及其周期求解的计算量。同时,运用Floquet稳定性理论,将理论计算与实验结果相结合分析了随系统控制参数改变钻杆系统周期运动的局部稳定性和分岔行为。
The effects of fluctuation of cutting force, the mass eccentricity and the hydrodynamic force of cutting fluid can be taken into consideration in the model of drilling shaft system. To solve the hydrodynamic force of cutting fluid, the variational form of Reynolds equation in hydrodynamic fluid was revised continuously to satisfy certain constraint conditions by variational constraint approach. By means of this approach, a perturbed equation could be obtained directly on the finite element equation. Consequently, nonlinear hydrodynamic force and their Jacobian were calculated simultaneously, and compatible accuracy has been obtained without increasing computational cost. In the stability analysis, the period of the periodic orbit of the nonlinear drilling shaft system was drawn into the governing equation of the system explicitly by changing the time scale, and was taken part into the iteration procedure of the shooting method as a parameter. Then the periodic orbit and its period of the drilling shaft system were determined rapidly. Combining theories with experiment, the local stability and bifurcation behaviors of periodic motions with the change of the drilling shaft design parameter value were obtained by the Floquet theory.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2009年第2期220-226,共7页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家"973"重点基础研究发展计划资助项目(2007CB707706)
陕西省自然科学基金资助项目(2007E213
2007E203)
关键词
槽孔
钻杆
非线性动力学
稳定性
分岔
Slot hole, Drilling shaft, Nonlinear dynamics, Stability, Bifurcation
