Experimental parameters identification of a flexible rotor system equipped with smart magneto-rheological bearing

Magnetorheological (MR) fluid is one of the most effective smart fluids with controllable rheological and viscoelastic properties that is used in semi-active vibration control of systems and structures. MR squeeze-film dampers (MRSFDs) are categorized among smart bearings with variable stiffness and damping properties, which enable vibration mitigation of rotary systems. In this aspect, precise modeling of the rotor systems equipped with MRSFDs and identifying their parameters are of paramount importance for analyzing the vibra-tion behavior of the system and developing control strategies. The present study aims to present the analytical tools and algorithms for identifying the parameters of flexible rotor systems equipped with MRSFDs. For this purpose, a rotor-bearing system test setup including a flexible rotor, two ball bearings, an MRSFD, and an un-balanced disk is designed and fabricated, and its governing equations of motions are derived using finite element (FE) methods. The parameters of the flexible rotor system, as well as the stiffness and damping coefficients of the bearings and nonlinear damping forces of the MRSFD, are then identified using the developed algorithm and the harmonic responses of the system as its input. The procedure is then validated by comparing the results of the FE model with identified parameters with those measured experimentally. It is shown that the developed algorithm and FE model are capable of accurately identifying the parameters of the flexible rotor-bearing system equipped with an MRSFD.

Automated summary

Magnetorheological fluid is an effective smart fluid used for vibration control. In this study, analytical tools and algorithms are presented for identifying the parameters of flexible rotor systems equipped with MR squeeze-film dampers. The developed algorithm and finite element model are shown to accurately identify the system parameters.