An asymmetric placed Jeffcott rotor system with nonlinear elastic support was considered

and the influences of constant maneuver load on the dynamics of the rotor system were studied numerically.By setting different constant maneuver loads

it was found that the relationship between the amplitude and the excitation frequency may lead to different phenomenons including:hysteresis region narrowing

disappearance and secondary jump.With the variation of the frequency ratio

the relationship between the amplitude and the constant maneuver load is changed significantly.Under certain excitation frequency

if the constant maneuver load crosses a critical value

the amplitude of the system can jump from a small level to a large one

and not drop down even though the load is reduced to zero.In addition

the offset of the rotor's axis is not closely related to the excitation frequency

but mainly depended on the amount of the constant maneuver load.