The response time of a cantilever rotor with a disk-type magnetorheological(MR) fluid damper operating in a shear mode were measured at different excitation modes

rotational speeds and magnetic flux densities of different MR fluids.It was shown that the response time of the MR fluid damper rotor system consisted of the initial response time

rapid response time and last slow response time.The initial response time was less than 100 milliseconds;the rapid response time was about 50～400 milliseconds and both were impossible to be within a few milliseconds.The initial response time and the rapid response time were related not only to the magnetic flux density

magnetic particle weight ratio in the MR fluid and rotational speed

but also to the operating mode of the power supply.The response time of the rotor system during switching the step current off was longer than that during switching the step current on.There was an initial delay time at either switching the step current on or off

which was caused by the magnetizing or de-magnetizing process.