A semiactive control scheme for a rotor-bearing system using a squeeze film damper with MR fluid

Squeeze-film dampers (SFD) are commonly used to passively control the vibration response in rotor-bearing systems because they can provide flexibility, damping and extend the so-called stability thresholds. More recently, SFD are combined with Magneto-Rheological (MR) or Electro-Rheological (ER) fluids to introduce a control mechanism to modify the rotordynamic coefficients and deal with the robust performance of the overall system response for higher operating speeds. There are, however, some theoretical and technological problems that complicate a more extensive use in industry. In this work the mathematical model of a Newtonian fluid SFD hydrodynamic behavior through the Reynolds equation is shown and it is considered a SFD using MR fluid to model, analyze and semiactively control a rotor-bearing system using finite element methods, including also the controllable viscoelastic properties associated to the MR fluid. This semiactive control scheme is combined with an acceleration scheduling of the rotor speed to stabilize and reduce as possible the overall system response in a Jeffcott-like rotor configuration passing through the first critical speeds. In addition, a Choi-Lee-Park polynomial model is analyzed and adapted in order to simplify the MR fluid dynamics and synthesized using sliding-mode control techniques. The SFD with Newtonian fluid is connected to a platform with a rotor-bearing system to validate and experimentally evaluate the system performance.