Comparison of semi-active damping strategies for magnetorheological sandwich beams

The purpose of this research is to measure the free-decay dynamics of a magnetorheological (MR) sandwich beam when influenced by a semi-active magnetic field and comparing the resulting damping performance to those of baseline fields. The research effort involved an experiment where the beam freely decayed while in a magnetic field that influences the MR sandwich beam, altering its damping performance. In addition to baseline cases of no magnetic field or a constant field, the electromagnet also had a field that would shut off after a set time and a field that would switch between a high and low field strength at a certain frequency. These results were also recreated numerically, which required an experimental modal analysis to gather certain material property data. The experimental findings showed little variation in the damping performance regardless of the magnetic field used, while the numerical analysis indicate that the magnetic fields would quicken damping, but only slightly. The results suggest that improvements to the sandwich beam structure may yield the greatest improvement in MR-fluid-based damping performance.