Research Article
Theoretical and Numerical Analysis of Coupled Axial-Torsional Nonlinear Vibration of Drill Strings
Table 1
The type of bifurcation corresponding to Figures
3 and
4 and the change of Floquet multipliers.
| Types of bifurcations | of the bifurcation point/ | The change of Floquet multipliers |
| Hopf bifurcation | 1.847 | |
| Hopf bifurcation | 4.907 | |
| Static bifurcation | 31.90 | |
| Static bifurcation | 16.19 | |
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