On the active control of a rotor-bearing system using shape memory alloy actuators: an experimental analysis

Currently, there is a constant demand for effective methods to mitigate the effect of vibration in rotating dynamic systems, especially when passing through the critical speeds. Among the most recent studies, the use of actuators based on smart materials can be highlighted, such as shape memory alloys (SMA). These materials can be incorporated into the bearings of such systems, with the purpose of reducing vibrations in a given frequency range. One of the main characteristics of SMA is the ability to promote a variation of stiffness and damping, affecting the vibration response of a mechanical system. The objective of this work was to design a rotor-bearing system with active bearing using SMA springs and a temperature control system based on fuzzy logic, aiming to reduce the amplitudes of vibration when passing through the first natural frequency of the system. Such a reduction occurs by means of the change in system‘s stiffness, obtained by changing the temperature of SMA springs between 30 and 70 °C. The experimental results showed reductions of the order of up to 60% in the amplitudes of displacement, during the passage through the resonance region.