Experimental response and vibrational characteristics of a slotted rotor

This paper proposes to perform experimental tests on the vibrational characteristics of a slotted rotor. Changes in the responses of the nx amplitudes are examined for small and deep slots that can be considered as open cracks. The evolutions of the orbital patterns and the 2x harmonic components near one-half of the first critical speed are investigated in details to propose an efficient indicator of the presence of slots in rotor: a special attention is given to both the comparison of the horizontal and vertical maximum amplitudes of the 2 x harmonic components, and changes in the size of the inside loop of orbits when the rotor is passing through one-half of the first critical speed. A huge experimental work considering the influences of the slot depth and the orientation of unbalance relative to the slot direction is investigated in order to examine the possibility of detecting the presence of a transverse slot in rotors. (C) 2008 Elsevier B.V. All rights reserved.