Vibration analysis and control of rotating composite shaft system using active magnetic bearings

Abstract

The main aim of the project is to utilize the active vibration control technique to reduce vibration in composite shaft system using three nodded beam element. The fiber reinforced polymer (FRP) composite shaft is studied in this paper considering it as a Timoshenko beam. Three different isotropic rigid disks are mounted on it and also supported by two active magnetic bearings at its ends. The work involves finite element, vibrational and rotor dynamic analysis of the system. Rotary inertia effect, gyroscopic effect kinetic energy and strain energy of the shaft are derived and studied. The governing equation is obtained by applying Hamilton’s principle using finite element method in which four degrees of freedom at each node is considered. Active control scheme is applied through magnetic bearings by using a controller containing low pass filter, notch filter, sensor and amplifier which controls the current and correspondingly control the stability of the whole rotor-shaft system. Campbell diagram, stability limit speed diagram and logarithmic decrement diagram are studied to establish the system stability. Effect of different types of stacking sequences are also studied and compared.