ACTIVE VIBRATION CONTROL OF A ROTATING BLADE BASED ON MACRO FIBER COMPOSITE

For a long time, blade vibration failure occupies a quite large proportion of the total failure of the complete aeroengine. Developing the vibration reduction technology is of great importance for reducing the weight, improving the performance and extending the life for the rotating blade structure. In the present paper, the active vibration control is investigated in the presence of the 2:1 internal resonance of a pre-deformed rotating blade through introducing the sensors and actuators made of macro fiber composite (MFC). The equations of motion of the proportional-derivative feedback closed-loop control system are established with the effects of the time delay. The evolution equations of the controlled system are derived via the perturbation analysis. The effects of the velocity gain, the displacement gain, the time delay and some other system parameters on the steady-state response and the stabilities of the controlled system are revealed by the application of the continuation method. The analytic solutions are in good agreement with those obtained from the numerical integration. The main findings of the present study are as followings: the time delay has a significant effect on the stabilities of the controlled system. When the time delay exceeds a certain value, the equilibrium points of the evolution equations lose their stability. At the same time, the closed-loop control system enters a new period motion with a large vibration amplitude. There exists a range of displacement gain in which the multi-valued phenomenon appears in the steady-state response of the controlled system. Moreover, the straight borderline between the stable and the unstable regions in the gains plane is destroyed due to this range. Inappropriate assignments of the velocity gain and the displacement gain will cause a new resonance in the close-loop control system. The research results lay the theoretical foundations for the vibration reduction of the blade structure.