Research Article

Mathematical Modeling and Analysis of Drill String Longitudinal Vibration with Lateral Inertia Effect

Table 6

The free vibration natural frequency in different conditions.

Boundary conditionsWithout lateral inertiaLateral inertia

The first-order natural frequency (rad/s)0.030.04
The second-order natural frequency (rad/s)0.050.06
The third-order natural frequency (rad/s)0.070.09