旋挖钻机钻杆纵向振动分析

Analysis on axial vibration of drill pipe of rotary drilling rig

视旋挖钻机钻杆为连续系统,对其纵向振动进行研究。建立两端均带有集中质量元件和弹簧元件的多级阶梯截面杆纵向振动模型,推导相邻钻杆振幅系数的传递矩阵,建立钻杆的复杂边界条件,在此基础上进行质量归一化处理,进而获得钻杆纵向振动的频率方程和正则振型。结合实例进行模态分析,并和几种简化模型的固有频率、正则振型进行对比分析。结果表明:可以将多级阶梯截面杆模型简化为等直杆模型,不建议将两端均带有集中质量元件和弹簧元件的模型简化为上端固定、下端只带有集中质量元件的模型。

The axial vibration of drill pipe of rotary drilling rig was analyzed when it was taken as a continuum model. Then the vibration model was established in which the drill pipe was used as a rod with multi-step changes in cross-section and the same concentrated mass and spring elements at both ends. Furthermore, the transfer matrix of the amplitude coefficients between the adjacent drill pipes and the complex boundary conditions by two equations were derived respectively. And then,quality normalization was presented, and the frequency equation and the normal mode-shape were received. The results obtained from series of comparative studies show that it is feasible to simplify the multi-stepped rod model to one of uniform rod,but it is not proper to simplify the model with concentrated mass and spring elements at both ends to a model clamped at one end and with concentrated mass at the other end.