This paper evaluates the performance of a Magneto-Rheological (MR) mount. T
he mount incorporates MR fluid in a conventional fluid mount to open and cl
ose an inertia track between the fluid chambers of the mount. It is shown t
hat such switching of the inertia track improves the mount's isolation effe
ct by eliminating the large transmissibility peak that commonly exists at f
requencies larger than the notch frequency for conventional fluid mounts. T
he switching frequencies of the MR mount are evaluated based on the paramet
ers of the mount. A simple control scheme for switching the mount between t
he open and closed states is proposed, and the performance of the controlle
d mount is compared with conventional mounts. A sensitivity analysis is con
ducted to evaluate the effect of parameter errors in estimating the switchi
ng frequencies and mount performance. The results show that the switching f
requencies can be accurately determined from mount parameters that are easi
ly measured or estimated.